Stabilized blends containing antioxidants

ABSTRACT

The present invention relates to functional fluid compositions containing antioxidants, and specifically stable compositions containing antioxidants with limited solubility in and/or limited compatibility with the functional fluids with which they are used. In particular the present invention deals with functional fluids used in internal combustion engines, such as engine oils, and antioxidants containing a phenolic or benzoic group, where the antioxidant is present in the functional fluid composition at levels that would otherwise cause the composition to be unstable and/or hazy.

BACKGROUND OF THE INVENTION

The present invention relates to functional fluid compositionscontaining antioxidants, and specifically stable compositions containingantioxidants with limited solubility in and/or limited compatibilitywith the functional fluids with which they are used.

Antioxidants and their importance to various types of functional fluidsare known. However, many antioxidants may only be used in limited waysdue to solubility and/or compatibility issues with the functional fluidsin which they are used. Many antioxidants, including phenolic or benzoicantioxidants, have limited solubility in functional fluids, such asengine oils, gear oils and greases. These antioxidants, when used atlevels above their solubility and/or compatibility limits, may fall outof the functional fluid composition over time and/or cause thecomposition to appear hazy or cloudy.

These are serious issues in the manufacturing and blending processes ofthe fluids as well as in the field. For example, a functional fluidadditive manufacturer would sell a homogeneous additive package ofperformance chemicals, which may then be added to a base oil to give afinal lubricant, which in turn is sold in tanks, drums, cans and plasticcontainers for final delivery of the lubricant to the equipment to belubricated. To maintain assurance of performance of the final lubricant,or any other functional fluid, in the equipment in which it is used, theconcentrate and the lubricant must remain homogeneous throughout thesesteps. In other words, all of the additives present must be compatiblewith each of the various materials it comes into contact with and/orfinds itself, from the additive package to the concentrate to the finalfluid. This stringent standard greatly limits the choices of andavailable treatment levels for many additives, including theantioxidants discussed herein. These antioxidants could provide improvedperformance to a functional fluid but are not widely used and/or are notused at the optimal level because the additive does not meet thesolubility and/or compatibility requirements discussed above.

In the field, functional fluid compositions that drop out one or morecomponents over time may not perform properly unless they are well-mixedbefore use, or may be removed by filters associated with the equipmentin which the functional fluid is used. The haziness and/or cloudiness ofa functional fluid, which may be measured as the fluid's turbidity, isoften seen as a sign the composition is not stable, or may be in anearly stage of separation and/or component drop out. Such conditions arenot desired in functional fluid compositions, for both performance andaesthetic related reasons. This reality has created constraints on theuse of various antioxidants, such as effective maximum treat rates.

Without these solubility and/or compatibility limitations on the use ofthese antioxidants, greater performance and equipment protection mightbe achievable, including for example extended life of a lubricant or alubricated piece of equipment such as engines, automatic transmissions,gear assemblies and the like. Improved fuel economy and viscositystability might be achievable as well. Greater performance may even beachievable with lesser amounts of chemical as well as greater amounts,depending on the selection of the more effective, but otherwise notsuitable chemicals from a compatibility or solubility standpoint whendelivered in a conventional manner.

There is a need for functional fluid compositions that contain higheramounts of antioxidants while still remaining stable and/or clear. Thereis particularly a need for functional fluid compositions, such as engineoil compositions, that contain phenolic or benzoic antioxidants, atlevels that would otherwise cause the composition to be unstable and/orhazy, as described above. The compositions and methods of the presentinvention overcome these constraints and thus allow the use of theseantioxidants at levels not otherwise possible while still maintainingthe stability and/or clarity of the functional fluid composition.

SUMMARY OF THE INVENTION

Functional fluid compositions have been discovered that may contain highamounts of antioxidants, and particularly antioxidants with limitedsolubility in and/or compatibility with the functional fluidcompositions in which they are used, allowing for the use of higheramounts of such antioxidants in these functional fluid compositions,while maintaining the stability, clarity, and/or compatibility of theoverall composition.

The present invention provides a composition that includes (a) a mediumcomprising a solvent, a functional fluid, or combinations thereof, (b)an antioxidant component that is not fully soluble in the medium, and(c) a stabilizing component that is soluble in (a) and that interactswith (b) such that (b)'s solubility in (a) is improved. In thesecompositions components (b) and (c) may be present in component (a) inthe form of dispersed particles having an average diameter of less than10 microns.

The invention provides for various antioxidants, including phenolicantioxidants, benzoic antioxidants, naphthenic antioxidants, alkylatedphenolic antioxidants, alkylated benzoic antioxidants, alkylatednaphthenic antioxidants, benzyl-amine antioxidants, phenyl-amineantioxidants, phenyl-benzyl-amine antioxidants, naphthyl-amineantioxidants, phenyl-naphthyl-amine antioxidants, alkylated phenyl-amineantioxidants, alkylated phenyl-benzyl-amine antioxidants, alkylatedphenyl-naphthyl-amine antioxidants, or any combination thereof.

The invention provides for various stabilizing, including anitrogen-containing dispersant, a borated nitrogen-containingdispersant, an alkyl borate, or any combinations thereof.

The invention provides for the compositions described herein where theturbidity of the overall composition is improved, as defined by visualclarity ratings (such as shown in Tables 1-3 below), or a lower JTUand/or NTU value compared to the same composition that does not contain(c), the stabilizing component.

The invention provides a process of preparing a clear and stablecomposition, where the composition includes: (a) a medium comprising asolvent, a functional fluid, or combinations thereof; and (b) anantioxidant component that is not fully soluble in the medium; and (c) astabilizing component that is soluble in (a) and that interacts with (b)such that (b)'s solubility in (a) is improved, where the method includesthe steps of: (1) adding components (b) and (c) to component (a), and(2) mixing the components so that particles of components (b) and (c),or in some embodiments particles of component (b) alone, have an averagediameter of less than 10 microns, or in other embodiments and morespecifically, no more than 10 percent by weight of the particles have adiameter of more than 0.5 microns. In addition, component (b) may bepresent in the overall composition at a minimum amount, such as no lessthan 0.05, or even 0.15 percent by weight. In some embodiments theclarity of the resulting mixture is improved, as defined by a lower JTUand/or NTU value compared to the same composition that does not contain(c), the stabilizing component.

DETAILED DESCRIPTION OF THE INVENTION

Various preferred features and embodiments will be described below byway of non-limiting illustration.

The present invention provides compositions and methods that allow forthe use of certain antioxidants in functional fluid compositions thatcould not otherwise be used, and/or could not be used at the levelsallowed for by the present invention, without resulting in unstable,unclear, and/or hazy compositions.

The types of functional fluids in and with which the compositions andmethods of the present invention may be used can include: gear oils,transmission oils, hydraulic fluids, engine oils, two cycle oils,metalworking fluids, fuels, greases, turbine oils, and the like. In oneembodiment the functional fluid is engine oil. In another embodiment thefunctional fluid is gear oil. In another embodiment the functional fluidis a transmission fluid. In another embodiment the functional fluid is ahydraulic fluid. In another embodiment the functional fluid is a fuel.In another embodiment the functional fluid is a grease.

In some embodiments the present invention does not include the use of adelivery device, for example a device that acts to contain theantioxidants and contact it with the functional fluid with which it isto be added. In some embodiments the present invention does not includethe use of either a gel composition or a solid composition, where suchcompositions slow release one or more components into a functionalfluid. Rather the present invention provides a means for incorporatingantioxidants into functional fluids, by use of a combination ofcomponents, which result in a functional fluid with the high level ofantioxidants while still being stable, clear and/or non-hazy.

In some embodiments the present invention provides a composition that ismore stable, clearer, and/or less hazy than a composition that isidentical except for it missing one or more components. In someembodiments the missing component is the stabilizing component. In otherembodiments the compositions of the present invention have a lowerturbidity compared to compositions that are identical except for themmissing the stabilizing component of the present invention. In some ofthese embodiments, the compositions' turbidity is expressed as a visualclarity rating such as in Tables 1-3 or a JTU and/or NTU value. In otherembodiments the compositions of the present invention have a maximum JTUand/or NTU value of 100, of 90 or even of 80.

JTU and NTU values may be measured US EPA method 180.1. JTU and NTUvalues may also be measured without any further dilution in JacksonTurbidity Units (JTU's) by using a Monitek Model 151 Turbidimeter.

The Medium

The compositions of the present invention include a medium. The mediummay be a solvent, a functional fluid, an additive concentrate, orcombinations thereof.

Suitable solvents include aliphatic hydrocarbons, aromatic hydrocarbons,oxygen containing compositions, or mixtures thereof. The oxygencontaining composition can include an alcohol, a ketone, an ester of acarboxylic acid, a glycol and/or a polyglycol, or a mixture thereof.Suitable solvents also include oils of lubricating viscosity, naphtha,toluene, xylene, or combinations thereof. The oil of lubricatingviscosity can comprise natural oils, synthetic oils, or mixturesthereof. The oil of lubricating viscosity can be an API (AmericanPetroleum Institute) Group II, III, IV, V base oil or mixture thereof.Suitable synthetic oils include polyolefin-based synthetic oils.Examples of commercially available aliphatic hydrocarbon solvents ordiluents, to include oils of lubricating viscosity, are Pilot™ 140 andPilot™ 299 and Pilot™ 900 available from Petrochem Carless,Petro-Canada™ 100N, Nexbase™, Yubase™, and 4 to 6 cStpoly(alpha-olefins). In some embodiments the functional fluid is amineral oil, a polyolefin-based synthetic oil, or a combination thereof.

Solvents useful in the present invention are not overly limited.Examples of organic solvents include alcohols such as methanol, ethanol,propanol, isopropanol, butanol, 3-methylbutanol, methyl isobutylcarbinol, heptanol, octanol, 2-ethyl-1-hexanol,3,3,5-trimethyl-1-hexanol, nonanol, cyclohexanol, benzyl alcohol,naphthyl alcohol, and fluoroalcohols; glycols such as ethylene glycol,diethylene glycol, triethylene glycol, polyethylene glycol, propyleneglycol, dipropylene glycol, and polypropylene glycol; ether alcoholssuch as 3-methoxybutanol, 3-methyl-3-methoxybutanol, ethylene glycolmonomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether(cellosolve), ethylene glycol monobutyl ether (butyl cellosolve),diethylene glycol monoethyl ether (carbitol), diethylene glycolmonobutyl ether (butyl carbitol), and propylene glycol monomethyl ether;ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone,cyclohexanone, and isophorone; heterocyclic compounds such aspyrrolidone, N-methylpyrrolidone, tetrahydrofuran, oxazole, benzofuran,and dioxane; amides such as dimethylformamide and dimethylacetamide;dimethylsulfoxide; sulfones such as sulfolane; esters such as methylacetate, ethyl acetate, butyl acetate, amyl acetate, 3-methoxybutylacetate, 3-methyl-3-methoxybutyl acetate, 2-ethylhexyl acetate,cyclohexyl acetate, benzyl acetate, methyl lactate, ethyl lactate, butyllactate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate;ethers such as dibenzyl ether and anisole; nitro compounds such asnitroethane and nitromethane; nitriles such as acetonitrile; lactonessuch as gamma-butyrolactone; ether esters such as ethylene glycolmonomethyl ether acetate, ethylene glycol monoethyl ether acetate, andpropylene glycol monomethyl ether acetate; aromatic hydrocarbons such asbenzene, toluene, xylene, cumene, cumene, dihexylbenzene,tetramethylbenzene, diethylbenzene, dibutylbenzene, biphenyl, mesityleneand cyclohexylbenzene; fused-ring hydrocarbons such as decalin,alkyldecalin, and tetralin; aliphatic hydrocarbons such as n-hexane,n-heptane, and mineral spirit; alicyclic hydrocarbons such ascyclohexane, alkylcyclohexane, and alkylcyclopentane; and others. Insome embodiments the solvent is an ether, such as dibenzyl ether,anisole, or combinations thereof.

In some embodiments the solvent is a dialkyl diphenyl ether, which maybe used in the preparation of specially grease and other lubricantapplication and which is known to have significant solubility problemswith many additives, limiting the ability to use is as a medium as wellas the additives that may be used with it.

Suitable functional fluids include any of the functional fluids listedabove, including mixtures of such fluids. In many embodiments thefunctional fluids, or other materials used as the medium, containadditional additives in addition to components (b) and (c) described indetail below. These additional additives are described in greater detailbelow.

In one embodiment of the invention the medium and/or the overallcomposition is substantially free of or free of at least one memberselected from the group consisting of sulphur, phosphorus, sulfated ash,and combinations thereof, and in other embodiments the fuel compositioncontains less than 20 ppm, less than 15 ppm, less than 10 ppm, or lessthan 1 ppm of at least one member selected from the group consisting ofsulphur, phosphorus, sulfated ash, and combinations thereof.

In one embodiment, the medium and the stabilizing component may be thesame material. That is one material may perform the functions of bothcomponents. For example when the invention is in the form of aconcentrate the medium present may act as a stabilizing component andvice versa. This concentrate may then be added to a functional fluid asa top treat and/or additive package, resulting in a stable andhomogeneous functional fluid which would otherwise be cloudy orincompatible in the absence of stabilizer component/medium material.

The Antioxidant

The compositions of the present invention include an antioxidantcomponent. The antioxidant component may include a least one antioxidantthat is not fully soluble and/or compatible in the medium and/orfunctional fluid in which it is to be used. By not fully soluble and/orcompatible, it is meant that the antioxidant, at least at someconcentrations and/or at least some portion or some component of theantioxidant, does not stay dissolved and/or suspended in the fluid towhich it is added, causes the fluid to appear hazy and/or cloudy, or anycombination thereof. In some embodiments, the antioxidant causes thefluid in which it is used to have hazy appearance or solid drop-out, oran NTU and/or JTU value above 80, 90 or even 100. In some embodimentsthis fluid is a functional fluid composition such as a finishedlubricant or an additive concentrate.

In some embodiments the antioxidant of the present invention is solubleand/or compatible with a fluid at low concentrations, but becomes lessthan soluble and/or compatible at higher concentrations. In someembodiments antioxidants suitable for use in the present invention arenot fully soluble and/or compatible, as defined above, when present in afluid at concentrations of or more than 0.05, 0.1, 0.5, 1.0, 1.5, 2.0,or 3.0 percent by weight. In other embodiments antioxidants suitable foruse in the present invention are not fully soluble and/or compatible, asdefined above, when present in a fluid at concentrations of or more than5, 10, 15, 20 or even 25 percent by weight.

In some embodiments the antioxidant of the present invention includes anantioxidant that contains a phenolic or aromatic amine group. Suitableantioxidants, which include those that have some solubility and/orcompatibility issue, as defined above, may include a aromatic amineantioxidant, a naphthenic antioxidant, an alkylated phenolicantioxidant, an alkylated aromatic amine antioxidant, an alkylatednaphthenic antioxidant, a phenyl-amine antioxidant, a naphthyl-amineantioxidant, a phenyl-naphthyl-amine antioxidant, an alkylatedphenyl-amine antioxidant, an alkylated phenyl-naphthyl-amineantioxidant, or a combination thereof.

In some embodiments the antioxidant component includes an alkylatedphenolic antioxidant, a phenyl-naphthyl-amine antioxidant, an alkylatedphenyl-amine antioxidant, an alkylated phenyl-naphthyl-amineantioxidant, or a combination thereof. In other embodiments theantioxidant component may include an alkylated diphenyl amineantioxidant, an alkylated phenyl-naphthyl amine antioxidant, asterically hindered phenolic antioxidant, or combinations thereof.

The antioxidant of the invention may include a compound that contains atleast one nitrogen atom, one or more aromatic or phenolic groups, and atleast one hydrocarbyl substituent groups.

The antioxidant may be present in the compositions of the invention atlevels of at least 0.1, 0.15, 0.2, 0.3, 0.5 or even 1.0 percent byweight. The antioxidant may be present at more than 1, 5 or even 10percent by weight, while in other embodiments the antioxidant may bepresent at less than 10, 7.5, 5, or even 4 or 3 percent by weight.

The compositions of the present invention, and specifically theantioxidant component, may optionally include one or more additionalantioxidants. These additional antioxidants may or may not have thesolubility and/or compatibility issues of the antioxidant describedabove. Also, these additional antioxidants may or may not help tostabilize the overall composition.

The Stabilizing Component

The compositions of the present invention include a stabilizingcomponent. The stabilizing component of the present invention is solublein medium and that interacts with the antioxidant such that itssolubility in the medium and/or overall composition is improved. Thismay be accomplished by an association of the stabilizing component andthe antioxidant, resulting in suspended particles of the associatedmolecules, that remain suspended, dispersed and/or dissolved in themedium and/or overall composition to an extent greater than obtained bythe antioxidant alone.

The stabilizing component of the present invention is an additive that,when combined with the antioxidant in the medium, results in animprovement in the turbidity of the composition, compared to the samecomposition that does not contain the stabilizing component.

In some embodiments, the stabilizing component may include: (i) anitrogen-containing dispersant, (ii) a borated nitrogen-containingdispersant; (iii) an alkyl borate, (iv) a low molecular weight acylatednitrogen compound, (v) a fatty acid derived amine salt of a salicylicacid, or any combination thereof. In other embodiments, the stabilizingcomponent may include: (i) a nitrogen-containing dispersant, (ii) aborated nitrogen-containing dispersant; (iii) an alkyl borate, (iv) alow molecular weight acylated nitrogen compound, or any combinationthereof, where the fatty acid derived amine salt of a salicylic acid mayin some embodiments be exclude from the stabilizing component, as itdoes not appear to provide as consistent performance as the otherstabilizing components described.

In some embodiments the stabilizing component includes anitrogen-containing dispersant or borated version thereof. Thenitrogen-containing dispersant may be a reaction product of ahydrocarbyl-substituted succinic acylating agent and a polyamine, whichmay optionally be borated. Such materials are described in U.S. Pat. No.4,234,435.

The hydrocarbyl-substituted succinic acylating agents can includesuccinic acids, halides, esters, and anhydrides. In some embodiments theagents are succinic anhydrides. In one embodiment thehydrocarbyl-substituted succinic acylating agents of the invention havea polyalkylene hydrocarbyl group, which may be linear and contain from12 to 20 carbon atoms. Suitable examples includes dodecenyl succinicanhydride, pentadecenyl succinic anhydride, hexadecenyl succinicanhydride, octadecenyl succinic anhydride, heptadecenyl succinicanhydride, and the like. In one embodiment, the hydrocarbyl groups ofthe acylating agents are derived from polyalkenes having an Mn (numberaverage molecular weight) of from 500, 750, or 850 up to 5000, 3000,2000, or 1600, and the polydispersity, (Mw/Mn), that is, the ratio ofthe weight average molecular weight over the number average molecularweight is from 1.5, 1.8, or 2, or to 2.5, 3.6, or 3.2. In someembodiments, the nitrogen free dispersant of the present invention isderived from a hydrocarbon polymer, such as polyisobutylene (PIB), thatsubstantially free of polymer having a Mn of more than 1600, or from1600 to 3000.

The PIB may be conventional PIB or highly reactive and/or highvinylidene PIB. In one embodiment the PIB used is conventional PIB, inanother embodiment the PIB used is highly reactive PIB, and in stillanother embodiment the PIB used is a mixture of conventional and highlyreactive PIB.

The amine which reacts with the succinic acylating agent may be apolyamine. The polyamine may be aliphatic, cycloaliphatic, heterocyclicor aromatic. Examples of the polyamines include alkylene polyamines,hydroxy containing polyamines, aromatic polyamines, and heterocyclicpolyamines.

Such alkylenepolyamines include ethylenepolyamines, butylenepolyamines,propylenepolyamines, pentylenepolyamines, etc. The higher homologs andrelated heterocyclic amines such as piperazines andN-aminoalkyl-substituted piperazines are also included. Specificexamples of such polyamines are ethylenediamine, diethylenetriamine(DETA), triethylenetetramine (TETA), tris-(2-aminoethyl)amine,propylenediamine, trimethylenediamine, tripropylenetetramine,tetraethylenepentamine (TEPA), hexaethyleneheptamine,pentaethylenehexamine, and mixtures thereof.

Suitable polyamines also include ethylenepolyamines, as described underthe heading Ethylene Amines in Kirk Othmer's “Encyclopedia of ChemicalTechnology”, 2d Edition, Vol. 7, pages 22-37, Interscience Publishers,New York (1965). These materials are a complex mixture ofpolyalkylenepolyamines including cyclic condensation products such asthe aforedescribed piperazines.

Other useful types of polyamine mixtures are those resulting fromstripping the above-described polyamine mixtures to leave a residueoften termed “polyamine bottoms”. In general, alkylenepolyamine bottomscan be characterized as having less than two, usually less than 1%, (byweight) material boiling below 200° C. A typical sample of such ethylenepolyamine bottoms obtained from the Dow Chemical Company of Freeport,Texas designated “E-100” has a specific gravity at 15.6° C. of 1.0168, apercent nitrogen by weight of 33.15 and a viscosity at 40° C. of 121centistokes. Gas chromatography analysis of such a sample contains 0.93%“Light Ends” (most probably DETA), 0.72% TETA, 21.74% TEPA and 76.61%pentaethylenehexamine and higher (by weight). These alkylenepolyaminebottoms include cyclic condensation products such as piperazine andhigher analogs of diethylenetriamine, triethylenetetramine and the like.These alkylenepolyamine bottoms can be reacted with the acylating agentalone or can be used with other amines and/or polyamines.

In some embodiments the nitrogen-containing dispersant is derived fromthe reaction of one or more of the amines described above and a fattycarboxylic acid. Suitable fatty carboxylic acids include both mono anddi carboxylic acids with a hydrocarbyl containing from 6, 10 or 12 to100, 60, 30, or 24 carbon atoms. The hydrocarbyl group may be linear orbranched, and in some embodiments contains a single methyl branch at theend of the hydrocarbyl chain. Specific examples of suitable acidsinclude dodecanoic acid, tetradecanoic acid, palmitic acid, stearic acid(including isostearic acid), icosanoic acid, and the like. Smaller acidscan be used in combination with those described above, such as adipicacid, succinic acid, octanedioic acid, and the like. In some embodimentsthese nitrogen-containing dispersants are prepared from isostearic acidand an alkylene polyamine such as DETA, TETA and/or TEPA.

The nitrogen-containing dispersants may also be borated. Typically, theborated dispersant contains from 0.1% to 5%, or from 0.5% to 4%, or from0.7% to 3% by weight boron. In one embodiment, the borated dispersant isa borated acylated amine, such as a borated succinimide dispersant.Borated dispersants are described in U.S. Pat. Nos. 3,000,916;3,087,936; 3,254,025; 3,282,955; 3,313,727; 3,491,025; 3,533,945;3,666,662 and 4,925,983. Borated dispersant are prepared by reaction ofone or more dispersants with one or more boron compounds. Any of thedispersants described herein may be borated, either during the reactionof the hydrocarbyl substituted acylating agent and the amine or after.

In one embodiment, the boron compound is an alkali or mixed alkali metaland alkaline earth metal borate. These metal borates are generallyhydrated particulate metal borates which are known in the art. Alkalimetal borates include mixed alkali and alkaline metal borates. U.S. Pat.Nos. 3,997,454; 3,819,521; 3,853,772; 3,907,601; 3,997,454; and4,089,790 disclose suitable alkali and alkali metal and alkaline earthmetal borates and their methods of manufacture. In one embodiment theboron compound is boric acid.

The nitrogen-containing dispersant may include a quaternary saltcomprising the reaction product of: (i) at least one compound selectedfrom the group consisting of: (a) the condensation product of ahydrocarbyl-substituted acylating agent and a compound having an oxygenor nitrogen atom capable of condensing with said acylating agent andsaid condensation product further having a tertiary amino group; (b) apolyalkene-substituted amine having at least one tertiary amino group;and (c) a Mannich reaction product having a tertiary amino group, saidMannich reaction product being prepared from the reaction of ahydrocarbyl-substituted phenol, an aldehyde, and an amine; and (ii) aquaternizing agent suitable for converting the tertiary amino group ofcompound (i) to a quaternary nitrogen, wherein the quaternizing agent isselected from the group consisting of dialkyl sulfates, benzyl halides,hydrocarbyl substituted carbonates; hydrocarbyl epoxides in combinationwith an acid or mixtures thereof.

In one embodiment the quaternary salt comprises the reaction product of(i) at least one compound selected from the group consisting of: apolyalkene-substituted amine having at least one tertiary amino groupand/or a Mannich reaction product having a tertiary amino group; and(ii) a quaternizing agent.

In another embodiment the quaternary salt comprises the reaction productof (i) the reaction product of a succinic anhydride and an amine; and(ii) a quaternizing agent. In such embodiments, the succinic anhydridemay be derived from polyisobutylene and an anhydride, where thepolyisobutylene has a number average molecular weight of about 800 toabout 1600. In some embodiments the succinic anhydride is chlorine free.

In some embodiments, the hydrocarbyl substituted acylating agent ofcomponent (i)(a) described above is the reaction product of a long chainhydrocarbon, generally a polyolefin substituted with a monounsaturatedcarboxylic acid reactant such as (1) monounsaturated C₄ to C₁₀dicarboxylic acid such as fumaric acid, itaconic acid, maleic acid; (2)derivatives of (1) such as anhydrides or C₁ to C₅ alcohol derived mono-or di-esters of (1); (3) monounsaturated C₃ to C₁₀ monocarboxylic acidsuch as acrylic acid and methacrylic acid; or (iv4 derivatives of (3)such as C₁ to C₅ alcohol derived esters of (3) with any compoundcontaining an olefinic bond represented by the general formula:

(R¹)(R¹)C═C(R¹)(CH(R¹)(R¹))

wherein each R¹ is independently hydrogen or a hydrocarbyl group.

Olefin polymers for reaction with the monounsaturated carboxylic acidscan include polymers comprising a major molar amount of C₂ to C₂₀, e.g.C₂ to C₅ monoolefin. Such olefins include ethylene, propylene, butylene,isobutylene, pentene, octene-1, or styrene. The polymers can behomopolymers such as polyisobutylene, as well as copolymers of two ormore of such olefins such as copolymers of; ethylene and propylene;butylene and isobutylene; propylene and isobutylene. Other copolymersinclude those in which a minor molar amount of the copolymer monomerse.g., 1 to 10 mole % is a C₄ to C₁₈ diolefin, e.g., a copolymer ofisobutylene and butadiene; or a copolymer of ethylene, propylene and1,4-hexadiene.

In one embodiment, at least one R of the compounds containing anolefinic bond described above is derived from polybutene, that is,polymers of C₄ olefins, including 1-butene, 2-butene and isobutylene. C₄polymers can include polyisobutylene. In another embodiment, at leastone R of the compounds containing an olefinic bond described above isderived from ethylene-alpha olefin polymers, includingethylene-propylene-diene polymers. Ethylene-alpha olefin copolymers andethylene-lower olefin-diene terpolymers are described in numerous patentdocuments, including European patent publication EP0279863 and thefollowing United States patents: 3,598,738; 4,026,809; 4,032,700;4,137,185; 4,156,061; 4,320,019; 4,357,250; 4,658,078; 4,668,834;4,937,299; 5,324,800 each of which are incorporated herein by referencefor relevant disclosures of these ethylene based polymers.

In another embodiment, the olefinic bonds of the compounds containing anolefinic bond described above are predominantly vinylidene groups,represented by the following formulas:

—(H)C═C(R²)(R²)

wherein R² is a hydrocarbyl group, and in some embodiments both R²groups are methyl groups, and

—(H)(R³)C(C(CH₃)═CH2)

wherein R³ is a hydrocarbyl group.

In one embodiment, the vinylidene content of the compounds containing anolefinic bond described above can comprise at least about 30 mole %vinylidene groups, at least about 50 mole % vinylidene groups, or atleast about 70 mole % vinylidene groups. Such material and methods forpreparing them are described in U.S. Pat. Nos. 5,071,919; 5,137,978;5,137,980; 5,286,823, 5,408,018, 6,562,913, 6,683,138, 7,037,999 andU.S. Publication Nos. 20040176552A1, 20050137363 and 20060079652A1,which are expressly incorporated herein by reference, such products arecommercially available by BASF, under the tradename GLISSOPAL® and byTexas Petrochemicals LP, under the tradename TPC 1105™ and TPC 595™.

Methods of making hydrocarbyl substituted acylating agents from thereaction of the monounsaturated carboxylic acid reactant and thecompounds containing an olefinic bond described above are well know inthe art and disclosed in the following patents: U.S. Pat. Nos. 3,361,673and 3,401,118 to cause a thermal “ene” reaction to take place; U.S. Pat.Nos. 3,087,436; 3,172,892; 3,272,746, 3,215,707; 3,231,587; 3,912,764;4,110,349; 4,234,435; 6,077,909; 6,165,235 and are hereby incorporatedby reference.

In another embodiment, the hydrocarbyl substituted acylating agent canbe made from the reaction of at least one carboxylic reactantrepresented by the following formulas:

(R⁴C(O)(R⁵)_(n)C(O))R⁴

and

wherein each R⁴ is independently H or a hydrocarbyl group, and each R⁵is a divalent hydrocarbylene group and n is 0 or 1 with any compoundcontaining an olefin bond described above. Compounds and the processesfor making these compounds are disclosed in U.S. Pat. Nos. 5,739,356;5,777,142; 5,786,490; 5,856,524; 6,020,500; and 6,114,547 which arehereby incorporated by reference.

Other methods of making the hydrocarbyl substituted acylating agent canbe found in the following reference, U.S. Pat. Nos. 5,912,213;5,851,966; and 5,885,944 which are hereby incorporated by reference.

The compound having an oxygen or nitrogen atom capable of condensingwith the acylating agent and further having a tertiary amino group canbe represented by the following formulas:

wherein X is an alkylene group containing about 1 to about 4 carbonatoms; and wherein each R⁶ is independently a hydrocarbyl group, andR^(6′) can be hydrogen or a hydrocarbyl group.

wherein X is an alkylene group containing about 1 to about 4 carbonatoms; and wherein each R⁷ is independently a hydrocarbyl group.

Examples of the nitrogen or oxygen contain compounds capable ofcondensing with the acylating agent and further having a tertiary aminogroup can include but are not limited to: ethylenediamine,1,2-propylenediamine, 1,3-propylene diamine, the isomericbutylenediamines, pentanediamines, hexanediamines, heptanediamines,diethylenetriamine, dipropylenetriamine, dibutylenetriamine,triethylenetetraamine, tetraethylenepentaamine, pentaethylenehexaamine,hexamethylenetetramine, and bis(hexamethylene) triamine, thediaminobenzenes, the diaminopyridines or mixtures thereof. In addition,nitrogen or oxygen contain compounds which may be alkylated to contain atertiary amino group may also used. Examples of the nitrogen or oxygencontain compounds capable of condensing with the acylating agent afterbeing alkylated to having a tertiary amino group can include but are notlimited to: dimethylaminopropylamine, N,N-dimethyl-aminopropylamine,N,N-diethylaminopropylamine, N,N-dimethyl-aminoethylamine or mixturesthereof. The nitrogen or oxygen containing compounds capable ofcondensing with the acylating agent and further having a tertiary aminogroup can further include aminoalkyl substituted heterocyclic compoundssuch as 1-(3-aminopropyl)imidazole and 4-(3-aminopropyl)morpholine,1-(2-amino ethyl)piperidine, 3,3-diamino-N-methyldipropylamine,3′3-aminobis(N,N-dimethylpropylamine). Another type of nitrogen oroxygen containing compounds capable of condensing with the acylatingagent and having a tertiary amino group include alkanolamines includingbut not limited to triethanolamine, N,N-dimethylaminoprop anol,N,N-diethylaminoprop anol, N,N-diethylaminobutanol,N,N,N-tris(hydroxyethyl)amine, or mixtures thereof.

The acid used with the quaternizing agent may be an organic acidrepresented by the general formula R—COOH where R is a hydrocarbylgroup. In some embodiments the hydrocarbyl group of the acid containsfrom 1 to 10, 1 to 6 or even 1 to 4 carbons atoms. In some embodimentsthe acid may be acetic acid, propionic acid, butyric acid, or petnanoicacid.

Examples of quaternary ammonium salt and methods for preparing the sameare described in the following patents, which are hereby incorporated byreference, U.S. Pat. No. 4,253,980, U.S. Pat. No. 3,778,371, U.S. Pat.No. 4,171,959, U.S. Pat. No. 4,326,973, U.S. Pat. No. 4,338,206, andU.S. Pat. No. 5,254,138

The quaternary salts of the invention may also comprise a polyesterquaternary ammonium salt which may be derived from the reaction of apolyester that contains a tertiary amino group and a quaternizing agentsuitable for converting the tertiary amino group to a quaternarynitrogen.

The polyester containing a tertiary amino group used in the preparationof the additives of the invention may also be described as anon-quaternized polyester containing a tertiary amino group.

In some embodiments the polyester is the reaction product of a fattycarboxylic acid containing at least one hydroxyl group and a compoundhaving an oxygen or nitrogen atom capable of condensing with said acidand further having a tertiary amino group. Suitable fatty carboxylicacids that may used in the preparation of the polyesters described abovemay be represented by the formula:

where R¹ is a hydrogen or a hydrocarbyl group containing from 1 to 20carbon atoms and R² is a hydrocarbylene group containing from 1 to 20carbon atoms. In some embodiments R¹ contains from 1 to 12, 2 to 10, 4to 8 or even 6 carbon atoms, and R² contains from 2 to 16, 6 to 14, 8 to12, or even 10 carbon atoms.

In some embodiments the fatty carboxylic acid used in the preparation ofthe polyester is 12-hydroxystearic acid, ricinoleic acid, 12-hydroxydodecanoic acid, 5-hydroxy dodecanoic acid, 5-hydroxy decanoic acid,4-hydroxy decanoic acid, 10-hydroxy undecanoic acid, or combinationsthereof.

The compound having an oxygen or nitrogen atom capable of condensingwith said acid and further having a tertiary amino group may include anyof the materials described above as compounds having an oxygen ornitrogen atom capable of condensing with the acylating agent. Suitablematerials may be represented by the formula:

where R³ is a hydrocarbyl group containing from 1 to 10 carbon atoms; R⁴is a hydrocarbyl group containing from 1 to 10 carbon atoms; R⁵ is ahydrocarbylene group containing from 1 to 20 carbon atoms; and X¹ is Oor NR⁶ where R⁶ is a hydrogen or a hydrocarbyl group containing from 1to 10 carbon atoms. In some embodiments R³ contains from 1 to 6, 1 to 2,or even 1 carbon atom, R⁴ contains from 1 to 6, 1 to 2, or even 1 carbonatom, R⁵ contains from 2 to 12, 2 to 8 or even 3 carbon atoms, and R⁶contains from 1 to 8, or 1 to 4 carbon atoms. In some of theseembodiments the compounds containing an olefinic bond described abovebecome:

where the various definitions provided above still apply.

Examples of nitrogen or oxygen containing compounds capable ofcondensing with the polyester agents include all of those listed aboveas examples of materials that are capable of condensing with theacylating agents.

The quaternized polyester salt can be a quaternized polyester amidesalt. In such embodiments the polyester containing a tertiary aminogroup used to prepare the quaternized polyester salt is a polyesteramide containing a tertiary amino group. In some of these embodimentsthe amine or amino alcohol is reacted with a monomer and then theresulting material is polymerized with additional monomer, resulting inthe desired polyester amide which may then be quaternized.

In some embodiments the quaternized polyester salt includes an anionrepresented by the following formula:

where R¹ is a hydrogen or a hydrocarbyl group containing from 1 to 20carbon atoms and R² is a hydrocarbylene group containing from 1 to 20carbon atoms; R³ is a hydrocarbyl group containing from 1 to 10 carbonatoms; R⁴ is a hydrocarbyl group containing from 1 to 10 carbon atoms;R⁵ is a hydrocarbylene group containing from 1 to 20 carbon atoms; R⁶ isa hydrogen or a hydrocarbyl group containing from 1 to 10 carbon atoms;n is a number from 1 to 10; R⁷ is hydrogen, a hydrocarbonyl groupcontaining from 1 to 22 carbon atoms, or a hydrocarbyl group containingfrom 1 to 22 carbon atoms; and X² is a group derived from thequaternizing agent. In some embodiments R⁶ is hydrogen.

As above, in some embodiments R¹ contains from 1 to 12, 2 to 10, 4 to 8or even 6 carbon atoms, and R² contains from 2 to 16, 6 to 14, 8 to 12,or even 10 carbon atoms, R³ contains from 1 to 6, 1 to 2, or even 1carbon atom, R⁴ contains from 1 to 6, 1 to 2, or even 1 carbon atom, R⁵contains from 2 to 12, 2 to 8 or even 3 carbon atoms, and R⁶ containsfrom 1 to 8, or 1 to 4 carbon atoms. In any of these embodiments n maybe from 2 to 9, or 3 to 7, and R⁷ may contain from 6 to 22, or 8 to 20carbon atoms.

In these embodiments the quaternized polyester salt is essentiallycapped with a C1-22, or a C8-20, fatty acid. Examples of suitable acidsinclude oleic acid, palmitic acid, stearic acid, erucic acid, lauricacid, 2-ethylhexanoic acid, 9,11-linoleic acid, 9,12-linoleic acid,9,12,15-linolenic acid, abietic acid, or combinations thereof.

The number average molecular weight (Mn) of the quaternized polyestersalts of the invention may be from 500 to 3000, or from 700 to 2500.

The polyester useful in the present invention can be obtained by heatingone or more hydroxycarboxylic acids or a mixture of thehydroxycarboxylic acid and a carboxylic acid, optionally in the presenceof an esterification catalyst. The hydroxycarboxylic acids can have theformula HO—X—COOH wherein X is a divalent saturated or unsaturatedaliphatic radical containing at least 8 carbon atoms and in which thereare at least 4 carbon atoms between the hydroxy and carboxylic acidgroups, or from a mixture of such a hydroxycarboxylic acid and acarboxylic acid which is free from hydroxy groups. This reaction can becarried out at a temperature in the region of 160 C to 200 C, until thedesired molecular weight has been obtained. The course of theesterification can be followed by measuring the acid value of theproduct, with the desired polyester, in some embodiments, having an acidvalue in the range of 10 to 100 mg KOH/g or in the range of 20 to 50 mgKOH/g. The indicated acid value range of 10 to 100 mg KOH/g isequivalent to a number average molecular weight range of 5600 to 560.The water formed in the esterification reaction can be removed from thereaction medium, and this can be conveniently done by passing a streamof nitrogen over the reaction mixture or, by carrying out the reactionin the presence of a solvent, such as toluene or xylene, and distillingoff the water as it is formed.

The resulting polyester can then be isolated in conventional manner;however, when the reaction is carried out in the presence of an organicsolvent whose presence would not be harmful in the subsequentapplication, the resulting solution of the polyester can be used.

In the said hydroxycarboxylic acids the radical represented by X maycontain from 12 to 20 carbon atoms, optionally where there are between 8and 14 carbon atoms between the carboxylic acid and hydroxy groups. Insome embodiments the hydroxy group is a secondary hydroxy group.

Specific examples of such hydroxycarboxylic acids include ricinoleicacid, a mixture of 9- and 10-hydroxystearic acids (obtained bysulphation of oleic acid followed by hydrolysis), and 12-hydroxystearicacid, and especially the commercially available hydrogenated castor oilfatty acid which contains in addition to 12-hydroxystearic acid minoramounts of stearic acid and palmitic acid.

The carboxylic acids which can be used in conjunction with thehydroxycarboxylic acids to obtain these polyesters are preferablycarboxylic acids of saturated or unsaturated aliphatic compounds,particularly alkyl and alkenyl carboxylic acids containing a chain offrom 8 to 20 carbon atoms. As examples of such acids there may bementioned lauric acid, palmitic acid, stearic acid and oleic acid.

In one embodiment the polyester is derived from commercial12-hydroxy-stearic acid having a number average molecular weight ofabout 1600. Polyesters such as this are described in greater detail inU.K. Patent Specification Nos. 1373660 and 1342746.

In some embodiments the components used to prepare the additivesdescribed above are substantially free of, essentially free of, or evencompletely free of, non-polyester-containing hydrocarbyl substitutedacylating agents and/or non-polyester-containing hydrocarbyl substituteddiacylating agents, such as for example polyisobutylene. In someembodiments these excluded agents are the reaction product of a longchain hydrocarbon, generally a polyolefin reacted with a monounsaturatedcarboxylic acid reactant, such as, (i) α,β-monounsaturated C₄ to C₁₀dicarboxylic acid, such as, fumaric acid, itaconic acid, maleic acid;(ii) derivatives of (i) such as anhydrides or C₁ to C₅ alcohol derivedmono- or di-esters of (i); (iii) α,β-monounsaturated C₃ to C₁₀monocarboxylic acid such as acrylic acid and methacrylic acid; or (iv)derivatives of (iii), such as, C₁ to C₅ alcohol derived esters of (iii)with any compound containing an olefinic bond represented by the generalformula (R⁹)(R¹⁰)C═C(R¹¹)(CH(R⁷)(R⁸) wherein each of R⁹ and R¹⁰ isindependently hydrogen or a hydrocarbon based group; each of R¹¹, R⁷ andR⁸ is independently hydrogen or a hydrocarbon based group and preferablyat least one is a hydrocarbyl group containing at least 20 carbon atoms.In one embodiment, the excluded hydrocarbyl-substituted acylating agentis a dicarboxylic acylating agent. In some of these embodiments, theexcluded hydrocarbyl-substituted acylating agent is polyisobutylenesuccinic anhydride.

By substantially free of, it is meant that the components of the presentinvention are primarily composed of materials other than hydrocarbylsubstituted acylating agents described above such that these agents arenot significantly involved in the reaction and the compositions of theinvention do not contain significant amounts of additives derived fromsuch agents. In some embodiments the components of the invention, or thecompositions of the invention, may contain less than 10 percent byweight of these agents, or of the additives derived from these agents.In other embodiments the maximum allowable amount may be 5, 3, 2, 1 oreven 0.5 or 0.1 percent by weight. One of the purposes of theseembodiments is to allow the exclusion of agents such as polyisobutylenesuccinic anhydrides from the reactions of the invention and so, to alsoallow the exclusion of quaternized salt detergent additive derived fromagents such as polyisobutylene succinic anhydrides. The focus of thisinvention is on polyester, or hyperdispersant, quaternary salt detergentadditives.

The quaternizing agents useful in preparing the quaternized polyestersalts described above include any of the quaternizing agents describedabove with regards to the other quaternized salts. In one embodiment,the quaternizing agent can be a hydrocarbyl epoxide in combination withan acid. Examples of hydrocarbyl epoxides include: ethylene oxide,propylene oxide, butylene oxide, styrene oxide and combinations thereof.In one embodiment the quaternizing agent does not contain any styreneoxide.

In some embodiments the acid used with the hydrocarbyl epoxide may be aseparate component, such as acetic acid. In other embodiments, forexample when the hydrocarbyl acylating agent is a dicarboxylic acylatingagent, no separate acid component is needed. In such embodiments, thedetergent may be prepared by combining reactants which are essentiallyfree of, or even free of, a separate acid component, such as aceticacid, and rely on the acid group of the hydrocarbyl acylating agentinstead. In other embodiments, a small amount of an acid component maybe present, but at <0.2 or even <0.1 moles of acid per mole ofhydrocarbyl acylating agent.

In some embodiments the quaternizing agent of the invention does notcontain any substituent group that contains more than 20 carbon atoms.In other words, in some embodiments the long substituent group thatallows for the resulting additive to be organic soluble and thus usefulfor the purposes of this invention is not provided by the quaternizingagent but instead is brought to the additive by the non-quaternizeddetergents described above.

In certain embodiments the molar ratio of detergent having an aminefunctionality to quaternizing agent is 1:0.1 to 2, or 1:1 to 1.5, or 1:1to 1.3.

In some embodiments the stabilizing component includes apoly(hydroxcarboxylic acid) amide salt derivative represented by theformula [Y—CO[O-A-CO]_(n)—Z_(r)—R⁺]_(m)pX^(q−) wherein Y is hydrogen ora substituted or non-substituted hydrocarbyl group for example a hydroxysubstituted hydrocarbyl group, A is a divalent hydrocarbyl group, n isfrom 1 to 100, m is from 1 to 4, q is from 1 to 4 and p is an integersuch that pq=m, Z is a divalent bridging group which is attached to thecarbonyl group through a nitrogen atom, r is 0 or 1, R′ is an ammoniumgroup and X^(q−) is an anion. In some embodiments the A in the formulaof the poly(hydroxycarboxylic acid) amide salt derivative is fullysaturated.

In some embodiments these stabilizing components are represented by theformula [Y—[O-A-CO]_(n)—Z_(r)—R⁺]_(m)pX^(q−) wherein Y is hydrogen, ahydrocarbonyl group (e.g. H-A-CO—), a hydrocarbyl group optionallysubstituted (e.g. H-A- or HO-A-) for example a hydroxy substitutedhydrocarbyl or hydrocarbonyl group (e.g. HO-A-CO—), A is a divalenthydrocarbyl group, n is from 1 to 100, m is from 1 to 4, q is from 1 to4 and p is an integer such that pq=m, Z is a divalent bridging groupwhich is attached to the carbonyl group through a nitrogen atom, r is 0or 1, R⁺ is an ammonium group and X^(q−) is an anion. In someembodiments the A in the formula of the poly(hydroxycarboxylic acid)amide salt derivative is fully saturated.

In still other embodiments these stabilizing components are representedby the formula [H—[O-A-CO]_((n+1))—Z_(r)—R⁺]_(m)pX^(q−) wherein A is adivalent hydrocarbyl group, n is from 1 to 100, m is from 1 to 4, q isfrom 1 to 4 and p is an integer such that pq=m, Z is a divalent bridginggroup which is attached to the carbonyl group through a nitrogen atom, ris 0 or 1, R⁺ is an ammonium group and X^(q−) is an anion. In someembodiments the A in the formula of the poly(hydroxycarboxylic acid)amide salt derivative is fully saturated.

The poly(hydroxycarboxylic acid) amide salt derivatives described abovemay also be referred to as hyperdispersants. The R⁺ group in theformulas above may be a primary, secondary, tertiary or quaternaryammonium group. In some embodiments R⁺ is a quaternary ammonium group.In some embodiments R⁺ in the hyperdispersant formula above isrepresented by formula —N⁺(R²)(R³)(R⁴) wherein R², R³ and R⁴ may beselected from hydrogen and alkyl groups such as methyl.

In the hyperdispersant formulas above A may be a divalent straight chainor branched hydrocarbyl group. A may be a substituted aromatic,aliphatic or cycloaliphatic straight chain or branched divalenthydrocarbyl group. In some embodiments A is an arylene, alkylene oralkenylene group, in particular an arylene, alkylene or alkenylene groupcontaining in the range of from 4 to 25, 6 to 25, 8 to 24, 10 to 22, oreven 12 to 20 carbon atoms. In some embodiments there are at least 4, 6,or even 8 to 14 carbon atoms connected directly between the carbonylgroup and the oxygen atom derived from the hydroxyl group. The optionalsubstituents in the group A may be selected from hydroxy, halo or alkoxygroups, especially C₁₋₄ alkoxy groups.

In the hyperdispersant formulas above n is in the range of from 1 to 100however the lower limit for n may also be 2 or 3. The upper limit for nmay be 100, 60, 40 20 or even 10. In other words n may be selected fromany of the following ranges: 1 to 100; 2 to 100; 3 to 100; 1 to 60; 2 to60; 3 to 60; 1 to 40; 2 to 40; 3 to 40; 1 to 20; 2 to 20; 3 to 20; 1 to10; 2 to 10; and 3 to 10.

In the hyperdispersant formulas above Y is an optionally substitutedhydrocarbyl group. Y may be aryl, alkyl or alkenyl containing up to 50carbon atoms, or in the range of from 7 to 25 carbon atoms. For example,the optionally substituted hydrocarbyl group Y may be convenientlyselected from heptyl, octyl, undecyl, lauryl, heptadecyl, heptadecenyl,heptadecadienyl, stearyl, oleyl and linoleyl. Other examples of Yinclude C₄₋₈ cycloalkyls such as cyclohexyl; polycycloalkyls such aspolycyclic terpenyl groups which are derived from naturally occurringacids such as abietic acid; aryls such as phenyl; aralkyls such asbenzyl; and polyaryls such as naphthyl, biphenyl, stilbenyl andphenylmethylphenyl. Y may contain one or more functional groups such ascarbonyl, carboxyl, nitro, hydroxy, halo, alkoxy, amino, preferablytertiary amino (no N—H linkages), oxy, cyano, sulphonyl and sulphoxyl.The majority of the atoms, other than hydrogen, in substitutedhydrocarbyl groups are generally carbon, with the heteroatoms (e.g.,oxygen, nitrogen and sulphur) generally representing only a minority,about 33% or less, of the total non-hydrogen atoms present. Thoseskilled in the art will appreciate that functional groups such ashydroxy, halo, alkoxy, nitro and cyano in a substituted hydrocarbylgroup Y will displace one of the hydrogen atoms of the hydrocarbyl,whilst functional groups such as carbonyl, carboxyl, tertiary amino(—N—), oxy, sulphonyl and sulphoxyl in a substituted hydrocarbyl groupwill displace a —CH— or —CH₂— moiety of the hydrocarbyl. In someembodiments Y is unsubstituted or substituted by a group selected fromhydroxy, halo or alkoxy group, for example a C₁₋₄ alkoxy group. In stillfurther embodiments Y is a stearyl group, 12-hydroxystearyl group, anoleyl group or a 12-hydroxyoleyl group, and that derived from naturallyoccurring oil such as tall oil fatty acid.

In the hyperdispersant formulas above Z may be an optionally substituteddivalent bridging group represented by the formula: —N(R¹)—B— wherein R¹is hydrogen or a hydrocarbyl group and B is an optionally substitutedalkylene group. Examples of hydrocarbyl groups that may represent R¹include methyl, ethyl, n-propyl, n-butyl and octadecyl. Examples ofoptionally substituted alkylene groups that may represent B includeethylene, trimethylene, tetramethylene and hexamethylene. Examples of Zmoieties include —NHCH₂CH₂—, —NHCH₂C(CH₃)₂CH₂— and —NH(CH₂)₃—.

In the hyperdispersant formulas above r is preferably 1, i.e. thepoly(hydroxycarboxylic acid) amide salt derivative must contain theoptionally substituted divalent bridging group Z.

The anion X^(q−) in the hyperdispersant formulas above is not criticaland can be any anion (or mixture of anions) suitable to balance thepositive charge of the poly(hydroxycarboxylic acid) amide cation. Theanion X^(q−) may be a sulphur-containing anion, such as sulphate andsulphonate anions. However, in some embodiments the anion X^(q−) is anon-sulphur-containing anion such as a non-sulphur-containing organicanion or inorganic anion. Non-limiting examples of suitable anions areOH⁻, CH⁻, NH₃ ⁻, HCO₃ ⁻, HCOO⁻, CH₃COO⁻, H⁻, BO₃ ³⁻, CO₃ ²⁻, C₂H₃O₂ ⁻,HCO²⁻, C₂O₄ ²⁻, HC₂O₄ ⁻, NO₂ ⁻, NO₂ ⁻, N³⁻, NH₂ ⁻, O²⁻, O₂ ²⁻, BeF₃ ⁻,F⁻, Na⁻, [Al(H₂O)₂(OH)₄]⁻, SiO₃ ⁻, SiF₆ ⁻, H₂PO₄ ⁻, P³⁻, PO₄ ³⁻, HPO₄²⁻, Cl⁻, ClO₃ ⁻, ClO₄ ⁻, ClO⁻, KO⁻, SbOH₆ ⁻, SnCl₆ ²⁻, [SnTe₄]⁴⁻, CrO₄²⁻, Cr₂O₇ ²⁻, MnO₄ ⁻, NiCl₆ ²⁻, [Cu(CO₃)₂(OH)₂]⁴⁻, ASO₄ ³⁻, Br⁻, BrO₃ ⁻,IO₃ ⁻, I⁻, CN⁻, OCN⁻, etc. Suitable anions may also include anionsderived from compounds containing a carboxylic acid group (e.g. acarboxylate anion), anions derived from compounds containing a hydroxylgroup (e.g. an alkoxide, phenoxide or enolate anion), nitrogen basedanions such as nitrate and nitrite, phosphorus based anions such asphosphates and phosphonates, or mixtures thereof. Non-limiting examplesof suitable anions derived from compounds containing a carboxylic acidgroup include acetate, oleate, salicylate anions, and mixtures thereof.Non-limiting examples of suitable anions derived from compoundscontaining a hydroxyl group include phenate anions, and mixturesthereof. In some embodiments the anion X^(q−) is a non-sulfur-containinganion selected from the group consisting of OH, a phenate group, asalicylate group, an oleate group and an acetate group, and in stillother embodiments the anion is OH.

The one or more poly(hydroxycarboxylic acid) amide salt derivatives maybe obtained by reaction of an amine and a poly(hydroxycarboxylic acid)of formula Y—CO[O-A-CO]_(n)—OH (I) wherein Y is hydrogen or optionallysubstituted hydrocarbyl group, A is a divalent optionally substitutedhydrocarbyl group and n is from 1 to 100, with an acid or a quaternizingagent. The Y, A and n in the poly(hydroxycarboxylic acid) formula may bedefined as above for the poly(hydroxcarboxylic acid) amide saltderivative formula.

As used herein, the term “hydrocarbyl” represents a radical formed byremoval of one or more hydrogen atoms from a carbon atom of ahydrocarbon (not necessarily the same carbon atoms in case more hydrogenatoms are removed). Hydrocarbyl groups may be aromatic, aliphatic,acyclic or cyclic groups. Preferably, hydrocarbyl groups are aryl,cycloalkyl, alkyl or alkenyl, in which case they may be straight-chainor branched-chain groups. Representative hydrocarbyl groups includephenyl, naphthyl, methyl, ethyl, butyl, pentyl, methylpentyl, hexenyl,dimethylhexyl, octenyl, cyclooctenyl, methylcyclooctenyl,dimethylcyclooctyl, ethylhexyl, octyl, isooctyl, dodecyl, hexadecenyl,eicosyl, hexacosyl, triacontyl and phenylethyl. The phrase “optionallysubstituted hydrocarbyl” is used to describe hydrocarbyl groupsoptionally containing one or more “inert” heteroatom-containingfunctional groups. By “inert” is meant that the functional groups do notinterfere to any substantial degree with the function of the compound.

In one embodiment at least one, or all of the poly(hydroxycarboxylicacid) amide salt derivatives are sulphur-containing derivatives. In suchan embodiment, said derivatives may have a sulphur content of at most2.5 wt. % for example from 0.1 to 2.0 wt. % or from 0.6 to 1.2 wt. %sulphur, as measured by ICP-AES, based on the total weight of saidderivatives. In another embodiment of the present invention, the one ormore poly(hydroxycarboxylic acid) amide salt derivatives arenon-sulphur-containing derivatives.

The group (—O-A-CO—) in the poly(hydroxycarboxylic acid)s and amide saltderivatives thereof described above may be a 12-oxystearyl group,12-oxyoleyl group or a 6-oxycaproyl group.

The amines which react with poly(hydroxycarboxylic acid)s to formpoly(hydroxycarboxylic acid) amide intermediates may include thosedefined in WO 97/41092. The amine reactant may be a diamine, a triamineor a polyamine. Suitable examples include diamines selected fromethylenediamine, N,N-dimethyl-1,3-propanediamine, triamines andpolyamines selected from diethylenetriamine, triethylenetetramine,tetraethylenepentamine, pentaethylenehex amine andtris(2-aminoethyl)amine.

The amidation between the amine reactant and the (poly(hydroxycarboxylicacid) may be carried out according to methods known to those skilled inthe art, by heating the poly(hydroxycarboxylic acid) with the aminereactant, optionally in a suitable hydrocarbon solvent such as tolueneor xylene, and azeotroping off the formed water. Said reaction may becarried out in the presence of a catalyst such as p-toluenesulphonicacid, zinc acetate, zirconium naphthenate or tetrabutyl titanate.

The poly(hydroxycarboxylic acid) amide intermediate formed from reactionof the amine and the poly(hydroxycarboxylic acid) is reacted with anacid or a quaternizing agent to form a salt derivative, according towell-known methods. Acids that may be used to form the salt derivativemay be selected from organic or inorganic acids. Said acids areconveniently selected from carboxylic acids, nitrogen-containing organicand inorganic acids, sulphur-containing organic or inorganic acids (suchas sulphuric acid, methanesulphonic acid and benzenesulphonic acid).

Quaternizing agents that may be used to form the salt derivative may beselected from dimethyl sulfate, a dialkyl sulphate having from 1 to 4carbon atoms, an alkyl halide such as methyl chloride, methyl bromide,aryl halide such as benzyl chloride. In one embodiment the quaternizingagent is a sulphur-containing quaternizing agent, in particular dimethylsulfate or an dialkyl sulphate having from 1 to 4 carbon atoms, forexample dimethyl sulphate. Quaternization is a well-known method in theart. For example, quaternization using dimethyl sulphate is described inU.S. Pat. No. 3,996,059, U.S. Pat. No. 4,349,389 and GB 1 373 660.

In some embodiments the poly(hydroxycarboxylic acid) amide saltderivatives have a TBN (total base number) value of less than 10 or evenless than 5 or less than 2 mgKOH/g, as measured by ASTM D 4739. Examplesof poly(hydroxycarboxylic acid) amide salt derivatives that areavailable commercially include that available from Lubrizol under thetrade designation “SOLSPERSE 17000” (a reaction product ofpoly(12-hydroxystearic acid) with N,N-dimethyl-1,3-propanediamine anddimethyl sulphate) and those available under the trade designations“CH-5” and “CH-7” from Shanghai Sanzheng Polymer Company.

In some embodiments the stabilizing component includes a high molecularweight polyetheramine, which may be prepared by reacting one unit of ahydroxy-containing hydrocarbyl compound with two or more units ofbutylene oxide to form a polyether intermediate, and aminating thepolyether intermediate by reacting the polyether intermediate with anamine or with acrylonitrile and hydrogenating the reaction product ofthe polyether intermediate and acrylonitrile.

Suitable polyetheramines may contain two or more ether units and isgenerally prepared from a polyether intermediate. The polyetherintermediate can be a reaction product of one unit of ahydroxy-containing hydrocarbyl compound with two or more units ofbutylene oxide. The hydroxy-containing hydrocarbyl compound can be analcohol or an alkyl-substituted phenol where the alcohol or alkylsubstituent of the phenol can have 1 to 50 carbon atoms, 6 to 30 carbonatoms in a second instance, and 8 to 24 carbon atoms in a thirdinstance. The alcohol or alkyl substituent of the phenol can have astraight carbon chain, branched carbon chain, or a mixture thereof. Thehydroxy-containing hydrocarbyl compound can contain one or more hydroxylgroups.

The polyether intermediate from the reaction of a hydroxy-containinghydrocarbyl compound and butylene oxide can have 2 to 100 repeatingbutylene oxide units, 5 to 50 repeating butylene oxide units in a secondembodiment, and 15 to 30 repeating butylene oxide units in a thirdembodiment. U.S. Pat. No. 5,094,667 provides reaction conditions forpreparing a polyether intermediate.

The high molecular weight polyetheramine of the present invention can beprepared from the above described polyether intermediate that isprepared from butylene oxide.

In one embodiment of the invention the polyetheramine is prepared byreacting the polyether intermediate derived from butylene oxide withacrylonitrile to form a nitrile that is then hydrogenated to form a3-aminopropyl terminated polyether as described in U.S. Pat. No.5,094,667.

In another embodiment of the invention the polyetheramine is prepared byreacting the polyether intermediate derived from butylene oxide with anamine in an amination reaction to give an aminated polyether asdescribed in European Publication No. EP310875. The amine can be aprimary or secondary monoamine, a polyamine containing an amino groupwith a reactive N—H bond, or ammonia.

The high molecular weight polyetheramine of the present invention canhave a number average molecular weight of 300 or 350 to 5000, in anotherinstance of 400 to 3500, and in further instances of 450 to 2500 and1000 to 2000.

In another embodiment of the invention the high molecular weightpolyetheramine of the present invention can be represented by theformula R(OCH₂CHR¹)_(x)A where R is a C₆ to C₃₀ alkyl group or a C₆ toC₃₀ alkyl-substituted phenyl group; R¹ is ethyl; x is a number from 5 to50; and A is OCH₂CH₂CH₂NH₂ or —NR²R³ wherein R² and R³ are independentlyhydrogen, a hydrocarbyl group, or —(R⁴NR⁵)_(y)R⁶ wherein R⁴ is analkylene group having 2 to 10 carbon atoms, R⁵ and R⁶ are independentlyhydrogen or a hydrocarbyl group, and y is a number from 1 to 7.Throughout this application an alkylene group is a divalent alkanegroup. In a further embodiment of the polyetheramine of the invention, Ris a C₈ to C₂₄ alkyl group, x is a number from 15 to 30, and A is—OCH₂CH₂CH₂NH₂.

In some embodiments the high molecular weight polyetheramine isrepresented by the formula R(OCH₂CHR¹)_(x)A wherein R is a C₆ to C₃₀alkyl group or a C₆ to C₃₀ alkyl-substituted phenyl group; R¹ is ethyl;x is a number from 5 to 50; and A is —OCH₂CH₂CH₂NH₂ or —NR²R³ wherein R²and R³ are independently hydrogen, a hydrocarbyl group, or—(R⁴NR⁵)_(y)R⁶ wherein R⁴ is an alkylene group having 2 to 10 carbonatoms, R⁵ and R⁶ are independently hydrogen or a hydrocarbyl group, andy is a number from 1 to 7.

In some embodiments the stabilizing component includes an alkanolaminesubstituted phenol where the phenol contains a hydrocarbyl substituent.Suitable materials may be represented by the formula:

where R1 is a hydrocarbyl group, R² is a hydrocarbylene group, each R³is independently a hydrocarbylene group, and each R⁴ is independently ahydrogen or a hydrocarbylene group. In some embodiments R¹ contains from1 to 20, 8 to 20, 8 to 16, 10 to 14 or even about 12 carbon atoms; R²contains from 1 to 8, 1 to 6, 1 to 4, at least 1 carbon atom, or evenabout 1 carbon atom; each R³ group contain from 1 to 8, 1 to 6, 1 to 4,2 to 4, at least 2 carbon atoms, or even about 2 carbon atoms and may beidentical; and each R⁴ group is hydrogen or a hydrocarbylene group thatcontains from 1 to 8, 1 to 6, 1 to 4, 2 to 4, at least 2 carbon atoms,or even about 2 carbon atoms and may be identical.

The nitrogen-containing dispersants of the present invention may also bepost-treated by reaction with any of a variety of agents besidesborating agents. Among these are urea, thiourea, dimercaptothiadiazoles,carbon disulfide, aldehydes, ketones, carboxylic acids,hydrocarbon-substituted succinic anhydrides, nitriles, epoxides, andphosphorus compounds. References detailing such treatment are listed inU.S. Pat. No. 4,654,403.

In one embodiment, the nitrogen-containing dispersant of the presentinvention is borated and may also be derived from PIB having an Mn ofless than 1600, or from 850 or 900 to 1500 or 1200.

The stabilizing component may be an alkyl borate. Suitable materialsinclude compounds that contain at least one B—O—R group where the R ishydrogen or a hydrocarbyl group. In some embodiments the alkyl borate isa trialkyl borate and has the general formula B(OR)3 where each R is ahydrocarbyl group that contains from 1 to 20, 4 to 20, 5 to 16 or even 6to 10 carbon atoms. In some embodiments each R is the same hydrocarbylgroup and contains 6 to 10 or even 8 carbon atoms. In some embodimentseach R group is a branched hydrocarbyl group.

Suitable examples of alkyl borates which may be used in the inventioninclude: tri-(2-methylpentyl) borate, tri-(2-ethylpentyl) borate,tri-(2-propylpentyl) borate, tri-(2-methylhexyl) borate,tri-(2-ethylhexyl) borate, tri(2-propylhexyl) borate,tri-(2-methylheptyl) borate, tri-(2-ethylheptyl) borate,tri-(2-propylheptyl) borate, or any combination thereof.

The stabilizing component may be a low molecular weight acylatednitrogen compound, which in some embodiments may be described as anamino ester or an amino ester salt. These materials may be prepared fromthe reaction of an alkyl succinic anhydride and an alkanolamine combinedat a ratio of 1:10 to 10:1, 1:5 to 5:1, 3:5 to 5:3, 1:2 to 2:1, 1:1. Thealkyl group of the alkyl succinic anhydride can be a hydrocarbyl groupcontaining from about 4 to about 18 carbon atoms; from about 6 to about18 carbon atoms, from about 9 to about 18 carbon atoms and particularlyfrom about 12 to about 18 carbon atoms. The alkyl group of the alkylsuccinic anhydride can be saturated, unsaturated, branched, linear ormixtures thereof. In some embodiments the alkyl group is linear.

The alkyl succinic anhydride can be the reaction product of a branchedor linear olefin having about 4 to about 18 carbon atoms; from about 6to about 18 carbon atoms, from about 9 to about 18 carbon atoms andparticularly from about 12 to about 18 carbon atoms and maleicanhydride. This reaction is well known to those skilled in the art.Suitable examples of the alkyl succinic anhydride include dodecenylsuccinic anhydride, pentadecenyl succinic anhydride, hexadecenylsuccinic anhydride, octadecenyl succinic anhydride, heptadecenylsuccinic anhydride, and the like.

The alkanolamine component of the acylated nitrogen compound of thepresent invention can be an amino alcohol, such as, an ethanolamine(including mono, di and tri ethanolamines), or a propanol amines(including mono, di and tri ethanolamines) in which nitrogen is attacheddirectly to the carbon of the alkyl alcohol. Examples of thealkanolamine component of the acylated nitrogen compounds can include:monoethanolamine, triethanolamine, methylethanolamine,methyldiethanolamine, dimethylethanolamine, diethylethanolamine,dibutylethanolamine, monoisoprop anolamine, diisoprop anolamine,triisopropanolamine. The examples of these alkanolamines are well knownto those skilled in the art. In some embodiments the alkanolamine usedin the preparation of the compatibilizer is triethanolamine,N,N-dimethylaminopropanol, N,N-diethylaminopropanol, N,N-dimethylethanolamine, N,N-diethylaminobutanol, N,N,N-tris(hydroxyethyl)amine, or amixture thereof.

The reaction products of the alkyl succinic anhydride or its acid orester derivative and the alkanolamine include amides, imides, esters,amine salts, ester-amides, ester-amine salts, amide-amine salts,acid-amides, acid-esters and mixtures thereof. The reaction and theresulting products of the alkyl succinic anhydride and the alkanolamineare readily known to those skilled in the art.

The stabilizing component may be an aromatic carboxylic acid/amine saltor an abietic acid/amine salt, that is a salt of an aromatic carboxylicacid and/or an abietic acid with an amine. However in other embodiments,these moderately performing stabilizing compounds may be excluded fromthe compositions of the invention, or at least required in higheramounts than some of the other stabilizing compounds described in orderto provide comparable performance. This is some embodiments thesematerials are part of the invention and in other embodiments the thesematerials may be treated more as comparative examples, at least wheremore consistent performance is required and/or at lower concentrationlevels.

The aromatic carboxylic acid may include an aliphatic moiety containingthe carboxylic acid group, and the aliphatic moiety may contain from 1to 26 or more carbon atoms, or from 1 to 10 carbon atoms. Alternatively,the aromatic carboxylic acid may be one in which the carboxylic group isbonded directly to the aromatic moiety, for example benzoic acid.Suitable aromatic carboxylic adds include benzoic acid, phenylaceticacid, phenylpropionic acid, phenylbutyric acid, phenylpentanoic acid,phenylhexanoic acid, phenylheptanoic acid, phenyloctanoic acid,phenylnonanoic acid, phenyldecanoic acid, phenyldodecanoic acid,phenyltetradecanoic acid, phenylbexadecanoic acid, andphenyloctadecanoic acid.

The aromatic carboxylic acid may also include phenyl versions of any ofthe acids described above, where a hydroxy group is present on thearomatic ring, generally adjacent to the aliphatic moiety containing thecarboxylic acid group. Examples of acids include salicylic acid.

The acid moiety of the amine salt may contain a hydroxy group, an oxygroup, or it may contain an ester moiety. Hydroxy carboxylic acidsinclude phenyl hydroxy carboxylic acids having a hydroxy alkyl groupwhich may contain from 3 to 26 carbon atoms. The phenyl or other arylring or rings may include one or more substituents attached theretoincluding alkyl groups of 1 to 12 or 10 more carbon atoms, alkoxy groupscontaining from 1 to 12 carbon atoms, hydroxy, carbamyl, carboalkoxy,amido or amino alkyl groups.

When one substituent group is present, not counting the hydroxy group ofa phenyl ring as a substituent if present, it may generally be in aposition para to the carboxylic acid moiety. When two or moresubstituents are present, they may generally be in a position 3,4 or 3,5on a phenyl ring. Illustrative examples include meta or para toluicacid, meta- or para-hydroxybenzoic acid, anisic acid and gallic acid.

The amine suitable for use in the preparation of the salt are not overlylimited and may include any alkyl amine, though generally are fatty acidamines derived from fatty carboxylic acids. The alkyl group present inthe amine may contain from 10 to 30 carbon atoms, or from 12 to 18carbon atoms, and may be linear or branched. In some embodiments thealkyl group is linear and unsaturated. Typical amines includepentadecylamine, octadecylamine, cetylamine, oleylamine, decylamine,dodecylamine, dimethyldodecylamine, tridecylamine, heptadecylamine,octadecylamine, stearylamine, and any combination thereof. In someembodiments the fatty acid derived amine salt of a salicylic acid ofoleylamine.

The salt is re prepared in any suitable manner and generally includesmixing the amines and acid under conditions designed to avoid conversionto the amide, ester, or other condensation products. In one embodiment,substantially equal molar proportions of the mine and acid are used.However, when desired, an excess of the amine may be employed, in whichcase the proportions may be in the range of from about 1.0 to about 1.2mole proportions of amine per mole proportion of acid.

In some embodiments the stabilizing component is a fatty acid aminosalicylate, that is an amine salt of salicylic acid where the amine usedin the preparation of the salt is derived from a fatty acid.

Amines suitable for use in the preparation of the amino salicylate arenot overly limited and may include any alkyl amine, though generally arefatty acid amines derived from fatty carboxylic acids. The alkyl grouppresent in the amine may contain from 10 to 30 carbon atoms, or from 12to 18 carbon atoms, and may be linear or branched. In some embodimentsthe alkyl group is linear and unsaturated. Typical amines includepentadecylamine, octadecylamine, cetylamine, oleylamine, decylamine,dodecylamine, dimethyldodecylamine, tridecylamine, heptadecylamine,octadecylamine, stearylamine, and any combination thereof. In someembodiments the fatty acid derived amine salt of a salicylic acid ofoleylamine.

Useful compatibilizers may be described more generally as a compoundhaving at least one hydrogen-donating group, a least onehydrogen-accepting group, and at least one hydrocarbyl group, where thehydrogen-donating group and the hydrogen-accepting group are notseparated by more than 8 bonds, where the bond counted may includecovalent bonds or ionic bonds, and generally both types of bondscombined.

In some embodiments the hydrocarbyl group of the compatibilizer compoundis sufficient to impart solubility to the compatibilizer in the mediumin which it is used, while in other embodiments it contains at least 8,10, 14 or even 20 carbon atoms. Is still other embodiments thehydrocarbyl group of the compatibilizer compound may be any of thehydrocarbyl groups defined above related to the compatibilizercomponent.

A hydrogen-donating group is a substituent group or atom capable ofdonating a proton to another compound. The group may itself be describedas a hydrogen donor group. Suitable examples of hydrogen-donating groupswhich are included in the invention are: —OH, —SH, —NRH, —NH₂, —NR₂H,—NRH₂, and —NH₃, where each R is independently a hydrocarbyl group.

A hydrogen-accepting group is a substituent group or atom capable ofaccepting a proton. The group may itself be described as a hydrogenacceptor group. Suitable examples of hydrogen-accepting groups which areincluded in the invention are: ═O, ═S, —NRH, —NRR, —NHH where each R isindependently a hydrocarbyl group; a carboxylic acid derivative such asa carboxylate anion, an inmide, an amide, an imidazoline, an anhydrideor an ester; or a phosphate or thiophosphate.

In other embodiments the accepting and donating groups discussed aboveare separated by at least 1 to no more than 6, 7 or 8 bonds, at least 2or even 3 to no more than 6, 7 or 8, and even no less than 2 up to nomore than 4 bonds. In some embodiments the compatibilizer compoundcontains at least one set of groups, that is at least one acceptor groupand at least one donating group, but in other embodiments thecompatibilizer compounds may contain multiple sets of groups. Forexample the compatibilizer compounds may include at least two acceptorgroups and at least two donating groups, or even more. Usefulcompatibilizer compounds may include 1 set of accepting and donatinggroups, two sets, or even three sets of groups. While not wishing to bebound by theory it is believed that the greater the number of sets ofaccepting and donating groups, the better a compounds performance as acompatibilizer, however the distance between the groups, as measured bythe number of bonds between the groups also has an impact oncompatibilizer performance. In addition it is believed that thefunctionality of the accepting and donating groups can be impaired ifthey are sterically hindered.

In other embodiments component (c), the stabilizing component, can be acompound represented by the formula:

or salted versions thereof wherein: X¹ is O or NR⁵ where R¹ and R⁵ canoptionally link to form a ring; R³ is H or a hydrocarbyl; R⁴ is H, ahydrocarbyl group, —CH₂C(O)—X² where X² is —OH, or where R⁴ is linkedwith R² to form a ring where the linked —R⁴—R²— is —CH₂C(O)—; andwherein each R¹ is independently H, a hydrocarbyl group or—(CH₂CH₂NH)_(n)—H where n is an integer from 1 to 10; where each R² isindependently H, a hydrocarbyl group or —(CH₂CH₂NH)_(n)—H where n is 1to 10, or where R² is linked with R⁴ to form a ring where the linked—R⁴—R²— group is —CH₂C(O)—; and R⁵ is a hydrocarbyl group; with theproviso that at least one of R¹, R², R³, R⁴, or R⁵ is a hydrocarbylgroup and wherein the entire compound contains at least 10 carbon atoms.In some embodiments at least one of R¹, R², R³, R⁴, or R⁵ is ahydrocarbyl group that contains at least 10 carbon atoms.

In still further embodiments component (c), the stabilizing component,can be a compound represented by one or more of the following formulas:

wherein each R⁶ is independently a hydrocarbyl group; each X³ isindependently a nitrogen containing group derived from a polyethylenepolyamine; and n may be an integer from 1 to 10.

In one embodiment, the nitrogen-containing dispersant of the presentinvention is any one or more of the following: a borated succinimidedispersant derived from the reaction of boric acid, a mixture ofpolyethylene polyamines and/or bottoms, and a polyisobutenyl succinicanhydride derived from conventional PIB; a borated succinimidedispersant derived from the reaction of boric acid, a mixture ofpolyethylene polyamines and/or bottoms, and a polyisobutenyl succinicanhydride derived from high vinylidene PIB; a borated dispersant derivedfrom the reaction of a polyisobutenyl succinimide dispersant and boricacid where the dispersant is derived from a mixture of polyethylenepolyamines and/or bottoms, and a polyisobutenyl succinic anhydridederived from conventional PIB; a non-borated polyisobutenyl succinimidedispersant derived from a polyisobutenyl succinic anhydride derived fromhigh vinylidene PIB and TEPA; a non-borated alkyl imidazoline derivedfrom a polyalkylene amine and a fatty mono-carboxylic acid.

In still other embodiments, the nitrogen containing dispersant used inthe stabilizing component of the present invention includes at least onehydrocarbyl group containing from 10, 20 or 40 to 500, 400 or 250 carbonatoms. The dispersant may also have a TBN (as defined below and asmeasured by ASTM D4739) of at least 9, 10, 15 or 20. In the case wherethe dispersant is borated, its TBN may be at least 9. In the case wherethe dispersant is not borated, its TBN may be at least 20. In furtherembodiments, where the dispersant is borated, it may contain at least0.1, 0.2, 0.4 percent by weight boron. The borated dispersant maycontain from 0.1, 0.2 or 0.4 to 4 or 2 percent by weight boron. In stillother embodiments, the dispersant may have an N:CO ratio of greater than0.7:1. The N:CO ratio of a dispersant is the ratio of the equivalents ofamino groups to carboxylic groups within the dispersant molecule. In thecase where the dispersant is borated, its N:CO ratio may be at least0.7:1 or at least 0.75:1. In the case where the dispersant is notborated, the N:CO ratio may have a higher limit, for example the N:COratio may be at least 1:1 or 1.3:1, or even at least 1.6:1. The N:COratio of the dispersants is generally not higher than 4:1, 3:1 or 2:1.Any one of the features describe above may be used in combination withthe others.

Any of the stabilizing components described above may be used alone,even to the exclusion of one or more the components listed, while inother embodiments they may be used in any combination of two or morethereof.

INDUSTRIAL APPLICATION

The present invention includes a process of preparing a composition thatincludes combining: (a) a medium comprising a solvent, a functionalfluid, or combinations thereof; (b) an antioxidant component that is notfully soluble in the medium; and (c) a stabilizing component that issoluble in (a) and that interacts with (b) such that (b)'s solubility in(a) is improved. The processes of the present invention involve addingcomponents (b) and (c) to component (a) and mixing the components sothat particles of components (b) and (c) have an average diameter ofless than 10 microns. The processes of the present invention results ina mixture that is clear and/or stable in that the antioxidant does notdrop out of solution, does not make the mixture appear cloudy or hazy,stays suspended, dispersed and/or dissolved in the mixture, orcombinations thereof, or that at least shows improvement in one or moreof these areas when compared to an identical composition that does notcontain the stabilizing component.

While not wishing to be bound by theory, it is believed that in at leastsome embodiments the compositions of the present invention improve thestability and/or compatibility of the antioxidant component in theoverall composition due to the antioxidant component being solubilizedin a complex with the compatibilizer.

In some embodiments the processes of the present invention result in amixture with an improved clarity, as defined by a lower JTU and/or NTUvalue, compared to the same composition that does not contain thestabilizing component.

In some embodiments the compositions of the present invention and/or thecompositions that result from the processes of the present inventioninclude both finished functional fluids and additive concentrates.Finished functional fluids are fluids that are ready for use. Additiveconcentrates are compositions that may contain all of the additivesrequired for a finished fluid, but in concentrated form. This makesshipment and handling easier. At the appropriate time, the additiveconcentrate may be blended with a fluid, solvent such as oil, or similardiluent, as well as additional additives, to produce a finishedfunctional fluid that is ready for use.

As noted above, components (b) and (c), or (b) alone, may be present incomponent (a) in the form of dispersed particles having an averagediameter of less than 10 microns. In some embodiments the particles havean average diameter of less than 10, 5 or 3 microns. In otherembodiments, the particles have an average diameter of from 0.01, 0.02,0.03 or 0.09 to 10, 6, 5 or 3 microns. In some embodiments 80% of theparticles meet one or more of the size limitations described above. Inother embodiments 90%, 95%, 99% or even 100% of the particles meet thesize limits. That is, in some embodiments no more than 10% by weight ofthe particles have a diameter of more than 10, 5, 3, 1 or even 0.5microns. The means by which the particles are formed is not overlylimited, and may include the mixing of components (a), (b) and (c) usingconventional equipment and/or techniques.

When referring to finished functional fluids, the compositions involvedwith the present invention may include: from 1, 3 or 10 to 99, 80 or 70percent by weight of component (a), the medium; from 0.1, 0.15, 0.2,0.3, 0.5 or 1.0 to 10, 7.5, 5, 4 or 3 percent by weight of component(b), the antioxidant; and from 0.1, 0.2, 0.3, 0.5 or 2.0 to 20, 10, 8,5, 4 or 2 percent by weight of component (c), the stabilizing component.

When referring to additive concentrates, the compositions involved withthe present invention may include: from 0.1, 1, 3 or 10 to 90, 60, 50,30, or 20 percent by weight of component (a), the medium; from 0.1,0.15, 0.5, 1, 5 or 8 to 60, 30, 20 or 10 percent by weight of component(b), the antioxidant; and from 0.1, 0.2, 0.3, 0.5 or 2.0 to 20, 10, 8,5, 4 or 2 percent by weight of component (c), the stabilizing component.As noted above in some embodiments the medium and the stabilizingcomponent, which may also be referred to as a compatibilizer orsolubilizer, may be the same material, in which case the duelfunctioning material may be present in any of the ranges provided abovefor either component (a) or (c).

In some embodiments the compositions of the present invention are formedby mixing components (b) and (c) into component (a) such that component(b) forms small particles within component (a) and component (c) acts tostabilize these particles. In some embodiments component (c) andcomponent (b) form mixed particles in component (a). In some embodimentssome or all of the particles formed are within the sizes describedabove. In other embodiments, some or even all of the particles arelarger than those described above.

In some embodiments the weight ratio of the compatibilizer to theantioxidant component is from 1:1 to 2:1.

In some embodiments the components of the present invention are mixed byconventional means. The amount of mixing required varies fromcomposition to composition and is that sufficient to produce theparticles of the desired size and/or stability. In some embodiments themixing may be accomplished by milling the components and in still otherembodiments the mixing may be accomplished by milling the components atlow temperature.

In one such embodiment, an antioxidant may be mixed into oil in thepresence stabilizing component, such as a succinimide dispersant. Themixing may be in the form of a milling process using conventionalmilling equipment and techniques. However, in some embodiments themilling is completed at low temperatures, in some embodiments from atless than 30 degrees C. and in other embodiments from −10, 0 or 5 to 30,25 or 20 degrees C. The low temperature milling may be achieved bycooled milling equipment, pre-cooled components, adding a chilling agentsuch as dry ice (solid carbon dioxide) to the components during milling,or a combination thereof. The resulting compositions in some embodimentsmay be described as stable dispersions and in other embodiments may bedescribed as solubilized solutions, or even combinations thereof, wherethe main difference between such embodiments may be the size of theparticles involved.

In other embodiments the compositions of present invention are notformed by milling or any other high-energy input methods, but rather areformed with simple mixing and very little energy input.

In some embodiments the functional fluid with which the compositions ofthe invention are used is a fuel. The fuel compositions of the presentinvention comprise the stabilized compositions described above and aliquid fuel, and is useful in fueling an internal combustion engine oran open flame burner. These compositions may also contain one or moreadditional additives described herein. In some embodiments, the fuelssuitable for use in the present invention include any commerciallyavailable fuel, and in some embodiments any commercially availablediesel fuel and/or biofuel.

The description that follows of the types of fuels suitable for use inthe present invention refer to the fuel that may be present in theadditive containing compositions of the present invention as well as thefuel and/or fuel additive concentrate compositions to which the additivecontaining compositions may be added.

Fuels suitable for use in the present invention are not overly limited.Generally, suitable fuels are normally liquid at ambient conditionse.g., room temperature (20 to 30° C.) or are normally liquid atoperating conditions. The fuel can be a hydrocarbon fuel,non-hydrocarbon fuel, or mixture thereof.

The hydrocarbon fuel can be a petroleum distillate, including a gasolineas defined by ASTM specification D4814, or a diesel fuel, as defined byASTM specification D975. In one embodiment the liquid fuel is agasoline, and in another embodiment the liquid fuel is a non-leadedgasoline. In another embodiment the liquid fuel is a diesel fuel. Thehydrocarbon fuel can be a hydrocarbon prepared by a gas to liquidprocess to include for example hydrocarbons prepared by a process suchas the Fischer-Tropsch process. In some embodiments, the fuel used inthe present invention is a diesel fuel, a biodiesel fuel, orcombinations thereof.

Suitable fuels also include heavier fuel oils, such as number 5 andnumber 6 fuel oils, which are also referred to as residual fuel oils,heavy fuel oils, and/or furnace fuel oils. Such fuels may be used aloneor mixed with other, typically lighter, fuels to form mixtures withlower viscosities. Bunker fuels are also included, which are generallyused in marine engines. These types of fuels have high viscosities andmay be solids at ambient conditions, but are liquid when heated andsupplied to the engine or burner it is fueling.

The non-hydrocarbon fuel can be an oxygen containing composition, oftenreferred to as an oxygenate, which includes alcohols, ethers, ketones,esters of a carboxylic acids, nitroalkanes, or mixtures thereof.Non-hydrocarbon fuels can include methanol, ethanol, methyl t-butylether, methyl ethyl ketone, transesterified oils and/or fats from plantsand animals such as rapeseed methyl ester and soybean methyl ester, andnitromethane.

Mixtures of hydrocarbon and non-hydrocarbon fuels can include, forexample, gasoline and methanol and/or ethanol, diesel fuel and ethanol,and diesel fuel and a transesterified plant oil such as rapeseed methylester and other bio-derived fuels. In one embodiment the liquid fuel isan emulsion of water in a hydrocarbon fuel, a non-hydrocarbon fuel, or amixture thereof.

In several embodiments of this invention the liquid fuel can have asulphur content on a weight basis that is 50,000 ppm or less, 5000 ppmor less, 1000 ppm or less, 350 ppm or less, 100 ppm or less, 50 ppm orless, or 15 ppm or less.

The liquid fuel of the invention is present in a fuel composition in amajor amount that is generally greater than 95% by weight, and in otherembodiments is present at greater than 97% by weight, greater than 99.5%by weight, greater than 99.9% by weight, or greater than 99.99% byweight.

The compositions described above may also include one or more additionaladditives. Such additives include friction modifiers, antiwear agents,corrosion inhibitors, or viscosity modifiers, as well as dispersant anddetergents different from those described above. These additionaladditives may be present in the medium, particularly when the mediumincludes a functional fluid. When present, these additional additivesmay represent from 0, 0.1, 0.5 or 1 to 2, 5, 10 or 15 percent of theoverall composition, when considering a finished fluid, and from 0, 0.5,1 or 2 to 4, 10, 20 or 40 percent of the overall composition, whenconsidering an additive concentrate.

As allowed for by the ranges above, in one embodiment, the additiveconcentrate may comprise the additives of the present invention and besubstantially free of any additional solvent. In these embodiments theadditive concentrate containing the additives of the present inventionis neat, in that it does not contain any additional solvent added toimprove the material handling characteristics of the concentrate, suchas its viscosity.

In the compositions of the invention, the concentration of component (b)in the overall composition may be at least 0.1, 1, 5 or even 10 percentby weight. The concentration of component (c) in the overall compositionmay be at least 10 or even 20 percent by weight. In some embodimentscomponent (c) is present in the composition from 24 to 60, 24 to 30, 24to 28 or even 24 too 27 percent by weight. In some of these embodiments,the total combined concentration of component (b) and component (c) inthe overall composition may be at least 20, 30, or even 34 percent byweight. In some embodiments the combined concentration of component (b)and component (c) in the overall composition is from 34 to 50, 34 to 40,34 to 38 or even 34 to 37 percent by weight.

As used herein, the term “hydrocarbyl substituent” or “hydrocarbylgroup” is used in its ordinary sense, which is well-known to thoseskilled in the art. Specifically, it refers to a group having a carbonatom directly attached to the remainder of the molecule and havingpredominantly hydrocarbon character. Examples of hydrocarbyl groupsinclude: hydrocarbon substituents, that is, aliphatic (e.g., alkyl oralkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, andaromatic-, aliphatic-, and alicyclic-substituted aromatic substituents,as well as cyclic substituents wherein the ring is completed throughanother portion of the molecule (e.g., two substituents together form aring); substituted hydrocarbon substituents, that is, substituentscontaining non-hydrocarbon groups which, in the context of thisinvention, do not alter the predominantly hydrocarbon nature of thesubstituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); heterosubstituents, that is, substituents which, while having a predominantlyhydrocarbon character, in the context of this invention, contain otherthan carbon in a ring or chain otherwise composed of carbon atoms.Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituentsas pyridyl, furyl, thienyl and imidazolyl. In general, no more than two,preferably no more than one, non-hydrocarbon substituent will be presentfor every ten carbon atoms in the hydrocarbyl group; typically, therewill be no non-hydrocarbon substituents in the hydrocarbyl group.

It is known that some of the materials described above may interact inthe final formulation, so that the components of the final formulationmay be different from those that are initially added. For instance,metal ions (of, e.g., a detergent) can migrate to other acidic oranionic sites of other molecules. In addition the acylating agentsand/or substituted hydrocarbon additives of the present invention mayform salts or other complexes and/or derivatives, when interacting withother components of the compositions in which they are used. Theproducts formed thereby, including the products formed upon employingthe composition of the present invention in its intended use, may not besusceptible of easy description. Nevertheless, all such modificationsand reaction products are included within the scope of the presentinvention; the present invention encompasses the composition prepared byadmixing the components described above.

Unless otherwise indicated all percent values and ppm values herein areweight percent values and/or calculated on a weight basis.

EXAMPLES

The invention will be further illustrated by the following examples,which sets forth particularly advantageous embodiments. While theexamples are provided to illustrate the present invention, they are notintended to limit it.

Example Set 1

A set of samples is prepared by adding a specific antioxidant known tohave compatibility issues to specific mediums. The antioxidant used inthis testing is an alkylated phenyl alpha-naphthyl amine (AO-1). Themediums used in this testing include: a polyolefin-based synthetic oil(MEDIUM-1), a mineral oil suitable for various applications includingengine oil (MEDIUM-2), and a mineral oil suitable for variousapplications including greases (MEDIUM-3). The compatibilizers used inthis testing include: a nitrogen containing dispersant derived from a1000 number average molecular weight polyisobutylene succinic anhydrideand a polyalkylene polyamine where the dispersant is itself about 15percent by weight oil (COMPAT-1), a borated nitrogen containingdispersant where the dispersant is derived from a 2000 number averagemolecular weight polyisobutylene derived succinic anhydride and amixture of polyalkylene polyamines, where the nitrogen to carbonyl ratioof the dispersant is about 1.5 and the molar ratio of boron to nitrogenin the borated dispersant is about 0.3 where the borated dispersantitself is bout 40 percent by weight oil (COMPAT-2), and a fatty aminesalt of salicylic acid (COMPAT-3).

Each example is heated up to 100 degrees Celsius and stirred untilclear. Each example is then cooled and stored at room temperature. Eachexample is then checked after 5 days, some are checked at 10 days, andall are checked at 4 weeks, with the time running from each sample beingplaced in storage. Each example is visually evaluated to check forcloudiness, haziness and even for drop out of the antioxidant.

The results from the example set are provided in the table below:

TABLE 1 Formulations¹ and Results² Comp Inv Comp Inv Comp Inv Comp InvEx 1 Ex 2 Ex 3 Ex 4 Ex 5 Ex 6 Ex 7 Ex 8 MEDIUM-1 80 60 MEDIUM-2 80 60MEDIUM-3 80 60 60 40 MEDIUM-4 AO-1 20 20 20 20 20 20 20 20 AO-2 COMPAT-120 20 COMPAT-2 20 COMPAT-3 20 40 COMPAT-4 COMPAT-5 COMPAT-6 5 DAYS DropClear Drop Clear Clear Clear Drop Clear Out Out Out 7-10 DAYS Clear DropClear Drop Clear Out Out 3 WEEKS Drop Drop Drop Clear Drop Clear DropClear Out Out Out Out Out ¹All formulation values in Table 1 are percentby weight. The compatibilizers tested may contain an inherent amount ofdiluent such as a diluent oil. ²Empty cells in the results sectionindicate no rating was taken for that sample at that time. A “Clear”rating indicates the sample was clear with no sediment, suspension orsolid dropout. A “Drop Out” rating indicates more than a light sedimentof solid materials did not remain in the liquid solution.

The results above show that the compositions of the inventionsurprisingly improve the solubility of the antioxidant when it iscombined with the compatibilizer of the invention. More specifically,Examples 2 and 4 compared to Comparative Examples 1 and 3 show theeffect the invention provides for an aromatic amine antioxidant using anitrogen containing dispersant in two different base oils mediums.Examples 6 and 8 compared to Comparative Examples 5 and 7 show theeffect the invention provides for an aromatic amine antioxidant using aborated nitrogen containing dispersant and a fatty amine salt ofsalicylic acid, respectively, in mineral oil base. Examples 9 to 12 showthe ability of various compatibilizers to improve the solubility of asterically hindered phenolic antioxidant in a medium useful in lubricantapplications that is known to have solubility issues with manyadditives.

Example Set 2

A second set of samples is prepared by adding a specific antioxidantknown to have compatibility issues to specific mediums. The antioxidantused in this testing is a sterically hindered phenolic antioxidantcommercially available from BASF (AO-2). The medium used in this testingis a dialkyl diphenyl ether suitable for various applications includingspecially grease applications (MEDIUM-4). The compatibilizers used inthis testing include: COMPAT-3 described above, a quaternary ammoniumsalt derived from a 1000 number average molecular weight polyisobutylenederived succinic anhydride and a polyalkylene polyamine, quaternizedusing an alkylene epoxide in combination with an acid (COMPAT-4), aborated nitrogen containing dispersant where the dispersant is derivedfrom a 1000 number average molecular weight polyisobutylene derivedsuccinic anhydride and a mixture of polyalkylene polyamines, where thenitrogen to carbonyl ratio of the dispersant is about 2 and the molarratio of boron to nitrogen in the borated dispersant is about 1 wherethe borated dispersant is itself about 30 percent by weight mineral oil(COMPAT-5), a low molecular weight acylated nitrogen compound(COMPAT-6), a alkyl phosphate alkyl amine salt (COMPAT-7), and a 400 TBNoverbased calcium sulfonate detergent with a total base number where thedetergent itself is about 40 percent by weight oil (COMPAT-8).Compatibilizer compounds COMPAT-7 and COMPAT-8 are included here incomparative examples, as is the example using COMPAT-3, at least at thisconcentration.

Each example is heated up to 100 degrees Celsius and stirred untilclear. Each example is then cooled and stored at room temperature. Eachexample is then checked after 5 days, some are checked at 10 days, andall are checked at 4 weeks, with the time running from each sample beingplaced in storage. Each example is visually evaluated to check forcloudiness, haziness and even for drop out of the antioxidant.

The results from the example set are provided in the table below:

TABLE 2 Formulations¹ and Results² Comp Comp Inv Inv Inv Comp Comp Ex 9Ex 10 Ex 11 Ex 12 Ex 13 Ex 14 Ex 15 MEDIUM-4 99.5 98.5 98.5 98.5 98.598.5 98.5 AO-2 0.5 0.5 0.5 0.5 0.5 0.5 0.5 COMPAT-3 1.0 COMPAT-4 1.0COMPAT-5 1.0 COMPAT-6 1.0 COMPAT-7 1.0 COMPAT-8 1.0 5 DAYS Suspen SuspenClear Clear Clear Suspen Suspen Trace Sed Trace Sed Trace Sed Trace SedTrace Sed Trace Sed 7 to 10 DAYS Suspen Suspen Clear Clear Clear SuspenSuspen Trace Sed Trace Sed Trace Sed Trace Sed Trace Sed Trace Sed 3WEEKS Suspen Suspen Clear Clear Clear Suspen Suspen Light Sed Light SedLight Sed Trace Sed Light Sed Light Sed ¹All formulation values in Table1 are percent by weight. The compatibilizers tested may contain aninherent amount of diluent such as a diluent oil. ²Empty cells in theresults section indicate no rating was taken for that sample at thattime. A “Clear” rating indicates the sample was clear. A “Drop Out”rating indicates more than a light sediment of solid materials did notremain in the liquid solution. A “Suspen” rating indicated a finesuspension was visible in the sample. A “Sed” rating indicates someamount of sediment was observed, with either a “trace” level or a“light” level indicating the amount. If any larger amount of sedimentwas observed the sample received a “drop out” rating.

The results above show that the compositions of the inventionsurprisingly improve the solubility of the antioxidant when it iscombined with the compatibilizer of the invention.

Example Set 3

A third set of samples is prepared by adding a specific antioxidantknown to have compatibility issues to specific mediums. The antioxidantused in this testing is a diphenyl amine antioxidant (AO-3). The mediumused in this testing is a mineral base oil (MEDIUM-5). Thecompatibilizers used in this testing include: COMPAT-2 described above,a trialkyl borate (COMPAT-9), and an ashless succinimide dispersantderived from a 2000 number average molecular weight polyisobutylenederived succinic anhydride and a mixture of polyalkylene polyamines,where the nitrogen to carbonyl ratio of the dispersant is about 0.8, andwhere the dispersant itself is about 50 percent by weight mineral oil(COMPAT-10).

Each example is mixed at 60 degrees Celsius and then observed to see ifthe sample is clear, or is solids are visible in the solution. Thesample is then mixed at 70 degrees Celsius and observed and so on at 10degree intervals up to 100 degrees Celsius. After the reading is takenat 100 degrees Celsius the sample is stored at 23 degrees Celsius andafter 5 days of storage each sample is again observed to see if it isclear or if solids are visible in the solution. Better compatibility isdemonstrate by obtaining a clear mixture at a lower mixing temperature,as well as having a clear sample after the storage time.

The results from the example set are provided in the table below:

TABLE 3 Formulations¹ and Results² Comp Inv Inv Comp Comp Inv Ex 16 Ex17 Ex 18 Ex 19 Ex 20 Ex 21 MEDIUM-5 90 66 46.2 74 80 66 AO-3 10 10 10 1010 10 COMPAT-2 24 COMPAT-9 24 27.4 10 COMPAT-10 16.4 16 Mix at 100 C.Clear Clear Clear Clear Clear Clear Mix at 90 C. Clear Clear Clear ClearClear Clear Mix at 80 C. Clear Clear Clear Clear Clear Clear Mix at 70C. Clear Clear Solids Clear Clear Mix at 60 C. Solids Clear Clear SolidsSolids Clear 5 DAYS Solids Slight Slight Solids Solids Slight SolidsSolids Solids ¹All formulation values in Table 1 are percent by weight.The compatibilizers tested may contain an inherent amount of diluentsuch as a diluent oil. ²Empty cells in the results section indicate norating was taken for that sample at that time. A “Clear” ratingindicates the sample was clear with no solids present. A rating of“Solids” indicates a significant amount of sediments was observed in thesample. A rating of “Slight Solids” indicates a very small amount ofsolids was visible in the sample.

The results above show that the compositions of the inventionsurprisingly improve the solubility of the antioxidant when it iscombined with the compatibilizer of the invention.

Each of the documents referred to above is incorporated herein byreference. Except in the Examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reaction conditions, molecular weights, number ofcarbon atoms, and the like, are to be understood as modified by the word“about.”

Unless otherwise indicated, each chemical or composition referred toherein should be interpreted as being a commercial grade material whichmay contain the isomers, by-products, derivatives, and other suchmaterials which are normally understood to be present in the commercialgrade. However, the amount of each chemical component is presentedexclusive of any solvent or diluent, which may be customarily present inthe commercial material, unless otherwise indicated. It is to beunderstood that the upper and lower amount, range, and ratio limits setforth herein may be independently combined. Similarly, the ranges andamounts for each element of the invention can be used together withranges or amounts for any of the other elements. As used herein, theexpression “consisting essentially of” permits the inclusion ofsubstances that do not materially affect the basic and novelcharacteristics of the composition under consideration. As used hereinthe term polyisobutenyl means a polymeric alkenyl group derived frompolyisobutylene, which may be a saturated or unsaturated group.

We claim:
 1. A composition comprising: (a) a medium comprising asolvent, a functional fluid, or combinations thereof; and (b) anantioxidant component that is not fully soluble in the medium; and (c) astabilizing component that is soluble in (a) and that interacts with (b)such that (b)'s solubility in (a) is improved; wherein components (b)and (c) are present in component (a) in the form of dispersed particleshaving an average diameter of less than 10 microns.
 2. The compositionof claim 1 wherein component (b), the antioxidant component, comprises aphenolic antioxidant, an alkylated phenolic antioxidant, a benzyl-amineantioxidant, a phenyl-amine antioxidant, a phenyl-benzyl-amineantioxidant, a naphthyl-amine antioxidant, a phenyl-naphthyl-amineantioxidant, an alkylated phenyl-amine antioxidant, an alkylatedphenyl-benzyl-amine antioxidant, an alkylated phenyl-naphthyl-amineantioxidant, or a combination thereof.
 3. The composition of claim 1wherein component (b), the antioxidant component, comprises an alkylateddiphenyl amine antioxidant, an alkylated phenyl-naphthyl amineantioxidant, a sterically hindered phenolic antioxidant, or combinationsthereof.
 4. The composition of claim 1 wherein component (c), thestabilizing component, comprises: (i) a nitrogen-containing dispersant;(ii) a borated nitrogen-containing dispersant; (iii) an alkyl borate;(iv) a low molecular weight acylated nitrogen compound; (v) a fatty acidderived amine salt of a salicylic acid; or combinations thereof.
 5. Thecomposition of claim 1 wherein the turbidity of the overall compositionis improved, as defined by a lower JTU and/or NTU value compared to thesame composition that does not contain (c), the stabilizing component.6. The composition of claim 1 wherein (b), the antioxidant component,comprises a compound containing at least one nitrogen atom, one or morearomatic groups, and at least one hydrocarbyl substituent group.
 7. Thecomposition of claim 1 wherein component (a), the medium, comprises: (i)a mineral oil; (ii) a polyolefin-based synthetic oil, or a combinationthereof.
 8. The composition of claim 1 wherein component (a), themedium, comprises a functional fluid selected from the group consistingof: gear oils, greases, turbine fluids, transmission oils, hydraulicfluids, engine oils, two cycle oils, metalworking fluids, fuels, oilfield or pipeline fluids, or a combination thereof.
 9. The compositionof claim 1 wherein component (c), the stabilizing component, comprises(i) a compound that contains at least one B—O—R group where the R ishydrogen or a hydrocarbyl group; (ii) a borated nitrogen-containingdispersant; or (iii) combinations thereof.
 10. The composition of claim1 wherein component (c), the stabilizing component, comprises aquaternary salt comprising the reaction product of: (i) at least onecompound selected from the group consisting of: (a) the condensationproduct of a hydrocarbyl-substituted acylating agent and a compoundhaving an oxygen or nitrogen atom capable of condensing with saidacylating agent and said condensation product further having a tertiaryamino group; (b) a polyalkene-substituted amine having at least onetertiary amino group; and (c) a Mannich reaction product having atertiary amino group, said Mannich reaction product being prepared fromthe reaction of a hydrocarbyl-substituted phenol, an aldehyde, and anamine; and (ii) a quaternizing agent suitable for converting thetertiary amino group of compound (i) to a quaternary nitrogen, whereinthe quaternizing agent is selected from the group consisting of dialkylsulfates, benzyl halides, hydrocarbyl substituted carbonates;hydrocarbyl epoxides in combination with an acid or mixtures thereof.11. The composition of claim 1 wherein the concentration of component(b) in the overall composition is at least 10 percent by weight.
 12. Thecomposition of claim 1 wherein the concentration of component (c) in theoverall composition is at least 10 percent by weight.
 13. Thecomposition of claim 1 wherein the total combined concentration ofcomponent (b) and component (c) in the overall composition is at least20 percent by weight.
 14. A process of preparing a clear and stablecomposition comprising: (a) a medium comprising a solvent, a functionalfluid, or combinations thereof; and (b) an antioxidant component that isnot fully soluble in the medium; and (c) a stabilizing component that issoluble in (a) and that interacts with (b) such that (b)'s solubility in(a) is improved; said method comprising the steps of: I. addingcomponents (b) and (c) to component (a); II. mixing the components sothat particles of components (b) and (c) have an average diameter ofless than 10 microns.
 15. The process of claim 13 wherein the clarity ofthe resulting mixture is improved, as defined by a lower JTU and/or NTUvalue compared to the same composition that does not contain (c), thestabilizing component.